Great question and great answers from Kulbir Singh jeeo - here is further thought process and views on the same "most difficult issues" for us jeeves on this planet:
The faults of false ego-sense (Haume) include lust (desire etc.), anger, greed, attachment to worldly objects due to delusion, and pride; and their numerous variations such as enviousness, stubborn mindedness, selfishness, shooting nonsense or excessive talking, and so on. The SGGS says that the lifestyle of a true devotee includes eradication of these Bikaars (negativity) from one's mind. Eradication of these Bikaars means eradication of one's Haume (false ego-sense). The lifestyle of true devotees is mentioned here by the SGGS to be "the most difficult", because it's very difficult to eradicate Haume and its faults (Bikaars). Which simply implies that — for most of us — "the most difficult thing" to do in life is to get rid of the Haume (false-ego sense)!
ਭਗਤਾ ਕੀ ਚਾਲ ਨਿਰਾਲੀ ॥ ਚਾਲਾ ਨਿਰਾਲੀ ਭਗਤਾਹ ਕੇਰੀ ਬਿਖਮ ਮਾਰਗਿ ਚਲਣਾ ॥ ਲਬੁ ਲੋਭੁ ਅਹੰਕਾਰੁ ਤਜਿ ਤ੍ਰਿਸਨਾ ਬਹੁਤੁ ਨਾਹੀ ਬੋਲਣਾ ॥ ਖੰਨਿਅਹੁ ਤਿਖੀ ਵਾਲਹੁ ਨਿਕੀ ਏਤੁ ਮਾਰਗਿ ਜਾਣਾ ॥: Bhagathaa kee chaal niraalee ...: The lifestyle of the devotees is unique and distinct. The devotees' lifestyle is unique and distinct; they follow the most difficult path. They renounce greed, avarice, pride and desire; they do not talk too much. The path they take is sharper than a two-edged sword, and finer than a hair (sggs 918).
ਹਉਮੈ ਸਭੁ ਸਰੀਰੁ ਹੈ ਹਉਮੈ ਓਪਤਿ ਹੋਇ ॥: Haumai sabh sareer hai hayumai opati hoi: Ego is within all the bodies; and through ego the beings are born (sggs 560).
ਹਉਮੈ ਵਿਚਿ ਪ੍ਰਭੁ ਕੋਇ ਨ ਪਾਏ ॥: Haumai vichi prabh koi na paae: No one finds God through egoism (sggs 664).
Therefore, renunciation or annihilation of one's ego is the true meditation — the real Jap, Tap and Sanjam. In other words, removal of one's ego is the true prayer (Ardaas), or Naam-Simran. Simply put, the ultimate victory is the disappearance of one's ego. The Gurbani indicates this to be "the most difficult thing" for us humans to accomplish.
ਸਿਮਰਹੁ ਰਾਮ ਨਾਮੁ ਅਤਿ ਨਿਰਮਲੁ ਅਵਰ ਤਿਆਗਹੁ ਹਉਮੈ ਕਉਰਾ ॥: Simarahu raam naam ath niramal avar thiaagahu houmai kouraa: Renouncing your ego, remember in meditation the most pure and sublime Lord's Name (sggs 415).
ਜਪੁ ਤਪੁ ਸੰਜਮੁ ਹਉਮੈ ਮਾਰਿ ॥: Jap Tap Sanjam houmai maar: Jap, Tap and Sanjam come by subduing the ego (sggs 1343).
ਆਪੁ ਛੋਡਿ ਬੇਨਤੀ ਕਰਹੁ ॥: Aap shod benatee karahu: Offer your prayers renouncing your false self: ego or Haume (sggs 295).
Thus, according to the SGGS, it is essential but very difficult for us humans to transcend identification with the body-mind-intellect personality (Haume). However, the infinite benefit one gains by this ultimate victory over ego (Haume) is Self-realization — the realization of one's True Nature as the Universal Self ("Joti-Svaroopa),or to experience that one's True Self and God, or simply Truth, are one and the same.
ਮਾਰਗੁ ਮੁਕਤਾ ਹਉਮੈ ਮਾਰਿ ॥: Maaragu muktaa houmai maar: The path of liberation is found by killing ego (sggs 1274).
ਜਪੁ ਤਪੁ ਸੰਜਮੁ ਹਉਮੈ ਮਾਰਿ ॥: Nanak houmai maari milaaiaa: O Nanak, conquering egoism, we are absorbed into the Divine (sggs 153).
ਹਉਮੈ ਮਾਰੇ ਤਾ ਦਰੁ ਸੂਝੈ ॥: Haumai maare taa dar soojhai: Kill your ego, then you will find God's Door (sggs 842).
ਸੋ ਜਨੁ ਸਾਚਾ ਜਿ ਹਉਮੈ ਮਾਰੈ ॥: So jan saachaa ji haumai maarai: That humble being is true, who kills his ego (sggs 230).
ਹਉਮੈ ਜਾਈ ਤਾ ਕੰਤ ਸਮਾਈ ॥: Hayumai jaaee taa kant samaee: Only by eliminating ego, you link with God (sggs 750).
ਨਾਉ ਮੰਨਿਐ ਹਉਮੈ ਗਈ ਸਭਿ ਰੋਗ ਗਵਾਇਆ ॥: Naaou maniai haumai gaee sabh rog gavaaiaa: With faith in the Divine Name, egoism is eradicated, and all sickness is cured (sggs 1242).
ਇਹੁ ਮਨੁ ਨਿਰਮਲੁ ਹਉਮੈ ਮਾਰੀ ॥: Ih mann nirmal hayumai maaree: The mind becomes pure when ego is killed (sggs 1049).
Accordingly, although it's the most difficult thing to do, still the SGGS time and again urges to to do it and be successful at it while still alive. For, as indicated in the SGGS, this is the only purpose of human life. The SGGS gives us clear vision of the ultimate Goal of human life, and the means to achieve that Goal. Therefore, it becomes essential for us, especially for a spiritual seeker, to gain true basic knowledge and understanding of the Gurbani. Such basic knowledge and understanding, in turn, will also help one understand Gurmukhs (Mahaatamaans, saintly beings etc.) to some extent.
Removal of this Haume — which is said to be the source of all human problems — is not an automatic process like digesting food. The SGGS never says it's an easy thing to do. Even with high education or material success in life, it is an extremely difficult feat. What is required as per the SGGS is a total inner transformation of our vision of life and its purpose.
ਭਈ ਪਰਾਪਤਿ ਮਾਨੁਖ ਦੇਹੁਰੀਆ ॥ ਗੋਬਿੰਦ ਮਿਲਣ ਕੀ ਇਹ ਤੇਰੀ ਬਰੀਆ ॥ ਅਵਰਿ ਕਾਜ ਤੇਰੈ ਕਿਤੈ ਨ ਕਾਮ ॥ ਮਿਲੁ ਸਾਧਸੰਗਤਿ ਭਜੁ ਕੇਵਲ ਨਾਮ ॥੧॥: Bhaee praapat maanukh dehureeaa. Gobind milan kee ih teree bareeaa. Avar kaaj terai kitai n kaam. Mil saadh sangat bhaj keval Naam ||1||: (You) have obtained (this) human body. This is your chance (time, opportunity...) to meet God. (If no effort is put forward to Realize God, then) all other efforts (work, ਉੱਦਮ) will be of no use (to your Soul). (Therefore) merge with the Saadhsangt and contemplate the Naam (Gur- or Aatm-Giaan...) alone ||1|| (sggs 12).
ਤਿਆਗਹੁ ਮਨ ਕੇ ਸਗਲ ਕਾਮ ॥: Tiaagahu man kae sagal kaam: Abandon all the desires of your mind (sggs1182).
ਕਾਮੁ ਕ੍ਰੋਧੁ ਲੋਭੁ ਮਨ ਤੇ ਤਿਆਗਿ ॥: Kaam krodhh lobh man thae thiaag: Drive out lust, anger and greed (i.e. all evil passions) from your mind (sggs 1271).
ਗੁਰਮੁਖਿ ਆਪਣਾ ਮਨੁ ਮਾਰਿਆ ਸਬਦਿ ਕਸਵਟੀ ਲਾਇ ॥ ਮਨ ਹੀ ਨਾਲਿ ਝਗੜਾ ਮਨ ਹੀ ਨਾਲਿ ਸਥ ਮਨ ਹੀ ਮੰਝਿ ਸਮਾਇ ॥: Guramukh aapanaa manu maariaa sabad kasavatee laai. Mann hee naal jhagarraa mann hee naal sath mann hee manjh samaai: Applying the Touchstone of the Shabad, by becoming the Gurmukh, the Gurmukh conqueres his mind (prevents it from falling in love with Maya, etc.). He fights with his mind (its evil inclinations: ਬਿਕਾਰ-ਬਿਰਤੀ), he settles with his mind (make his mind understand), and he becomes immersed (in the auspicious nature of: ਸ਼ੁਭ-ਬਿਰਤੀ) his mind (sggs 87).
ਛੋਡਿ ਸਗਲ ਸਿਆਣਪਾ ਮਿਲਿ ਸਾਧ ਤਿਆਗਿ ਗੁਮਾਨੁ ॥: Shod sagal siaanapaa mil saadh tiaag gumaan: Abandon all your clever tricks; meet with the Holy (Saadh-Sangat), and renounce your false pride (sggs 1006).
Not an easy path to tread! According to the SGGS, the path " is sharper than a two-edged sword, and finer than a hair". However, nevertheless, as indicated in the SGGS, it's a treadable path. But it's up to us to do our part. For example, if we want light in our room, we have to make the effort to at least turn the switch on in that room. Similarly, to tread this path, the SGGS urges us to put forward our best effort (Uddam) to advance along the spiritual path {moving from Manmukhtaa or materiality (Haume-consciousness} to Gurmukhtaa (Divine Lifestyle), sincerely loving the Guru by following His words (Gur-Shabad), sincerely performing our spiritual practices (Naam-Simran, keeping Saadh-Sangat etc.); trying to cultivate divine qualities like truthfulness, contentment, Knowledge (Aatam-Giaan), compassion, humility, detachment, patience, acceptance, love, and so on. But, as indicated in the SGGS, very "rare" one embarks on this path! Rest of us just remain entangled in the enchanting worldly objects and waste away.
ਗੁਣ ਸੰਜਮਿ ਜਾਵੈ ਚੋਟ ਨ ਖਾਵੈ ਨਾ ਤਿਸੁ ਜੰਮਣੁ ਮਰਣਾ ॥: Gun sanjam jaavai chot n khaavai naa tis jamman maranaa: One who departs with Sanjam of virtues is not struck down, and is not consigned to the cycle of birth and death (sggs76).
ਗੁਣ ਅੰਤਰਿ ਨਾਹੀ ਕਿਉ ਸੁਖੁ ਪਾਵੈ ਮਨਮੁਖ ਆਵਣ ਜਾਣਾ ॥: Gun antar naahee kiou sukh paavai Manmukh aavan jaanaa: With no virtues within, how can you find Sukha? The self-willed Manmukh comes and goes in reincarnation (sggs 76).
ਸਤਿਗੁਰਬਚਨਕਮਾਵਣੇਸਚਾਏਹੁਵੀਚਾਰੁ॥