What should we do regarding a Muslim who died of AIDS, whose body is shrouded in a plastic bag and cannot be uncovered, concerning washing, shrouding, praying over, and burying him?

If it is highly probable that there is a harmful infection caused by opening the shroud from the deceased, then tayammum should be performed over the shroud by wiping his face and hands. Then, the funeral prayer should be offered for him and he should be buried, in accordance with the Almighty's saying: (So fear Allah as much as you are able).