Sister's friend gave her his 2017 MacBook Pro, but didn't sign out

Hi, so 2 years ago my sister's friend gave her his 2017 Macbook Pro, but he didn't sign out from being the main user, his user account is still in the MacBook, Apple ID, as well as all of his info is still linked to it, do I just contact him, it would be helpful for my family to have this computer available to them, thank you for your time