i have a stock 1996 xj sport
my question is how do you replace the headliner there is no foam board and do you have to remove the sunroof

 

I have the same question. 98 Cherokee sport with sunroof, it doesn't feel like there is a backer board behind the sagging headliner. Anyone?

 

Headliners sag, especially in humid & hot temps. There are crossmembers that your headliner's foam once backed up against when it was fresh out of the factory and rigid enough that the paneling on the cieling held it in place. Replace the headliner (junkyards=recycling), or find the crossmembers, carefully drill holes, and use "interior trim fasteners" to hold the headliner up to them. They're running from Passenger to Driver's side. If the fabric is coming undone, remove the headliner and in some cases you can use a spray-adhesive. Keep in mind though, that most fabric adhesives will come undone in extreme hot or cold temperatures. You can remove it by using a Torx bit to remove the cieling handles and a phillips to remove the trim, then drawing it out the back while a friend helps support it (you don't want it to fold).