Randy H. answered 07/21/19
Experienced, Patient Computer Trainer with 30 Years Experience
Depends on the Mac model, and version inside that model line.
Some versions don't let you do it at all. Others are as easy as unsnapping a small cover and remove/replace. Still others require you to essentially disassemble the entire system to remove/replace.
Without more definitive information, it's hard tellin' not knowin' ...