Unblock or delete iCloud account

Hi everyone, the son of a friend died and leaved a mac and an iphone which i'm interested to buy, unfortunately he did not give their parents the unlock pass of both devices, as the kid wanted to have his life private his parents want to respect that, so they don't want to unlock the devices, they want to delete the accounts and therefore the pass of both account so i could use them. Is it possible? i read that apple ask for a desease certificate and this can only be done by the family. How to start the process? We are in Chile not in the USA.