What must be done by an elderly, blind maternal uncle who performed Hajj four years ago but forgot the Tawaf al-Ifadah and was unable to perform the Farewell Tawaf, in order to complete his Hajj, and is it permissible for him to appoint someone to perform the Tawaf on his behalf?

Your maternal uncle is still in a state of ihram, because the Tawaf al-Ifadah (circumambulation of outpouring) is a pillar of Hajj, and the greater disengagement from ihram (Al-Tahlul al-Akbar) is not complete without it. He must: refrain from marital intimacy and go to Mecca to perform the Tawaf al-Ifadah. It is recommended that he enter Mecca with an Umrah and then perform the Tawaf al-Ifadah. The Tawaf al-Ifadah is sufficient for the Tawaf al-Wada' (farewell circumambulation) if he departs immediately thereafter. He is not permitted to appoint someone else to perform the Tawaf on his behalf, as it is a pillar. If he is unable to come to Mecca due to illness or financial inability, some scholars consider him to be like one who is prevented (from completing Hajj), so he should slaughter a sheep and exit ihram, but the obligation of Hajj al-Islam remains upon him.