It's called a headliner.
Could you replace it yourself, maybe, it depends on how crafty you are. You may want to have it done professionally so that you don*t have problems with it coming down later. But it is something you could probably do yourself.
Here are some websites that I found to help you decide. Good luck.
〉 Answered on Aug 9th, 2008 by Lori Johnson, Owner and Instructor at Ladies Start Your Engines