Separating a computer from an Apple ID

Well over a decade ago, I set up a computer for my parents. At the time, Apple ID was not what it is today and I just used mine to set up the computer. Fast forward to present day. My parents have their own Apple ID on their iPads and iPhones, but their computer (yes, they share one) is still set up using my Apple ID. Can we change the computer to one of their Apple IDs without losing the files and software they have on that computer? How would I go about doing this? We are all in the same "family" with our Apple IDs.