All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
If the deceased made a will to donate any part of his body after his death or that his heirs permitted it, then this is permissible. However, they are not permitted to sell any part or limb of his body, only donating them is allowed.
Allaah Knows best.