Read:

http://www.brickboard.com/FAQ/700-900/InteriorTrimandPanels.htm#HeadlinerDIY

A wagon would be easier than a sedan as you can remove the headliner straight out the tail gate. You can get the fabric from various on-line sources and it's not all that expensive. You need to use 1/8" thick vs 1/4" otherwise the sunroof won't work right. Also, the 1/8" would conform easier to areas like the head well over the back seat.

Instead of disassembling the sunroof to recover it, I found it fairly easy to just drop the back end of the drain pan and slide the inner sunroof panel out of the back end of it.