If you don't want to hack in, get the parents to contact the places they want to access and they may have to send a copy of the death certificate to validate the reasons, but I had to do this for the wife of a friend who passed to get access to files online that were important to the family.
Once they received the paperwork the places she needed reset the passwords so she could log in and get what she needed.
Slashdot Mirror
If you don't want to hack in, get the parents to contact the places they want to access and they may have to send a copy of the death certificate to validate the reasons, but I had to do this for the wife of a friend who passed to get access to files online that were important to the family. Once they received the paperwork the places she needed reset the passwords so she could log in and get what she needed.