dude its easy.
1st- go to home depot, auto-zone, etc. and get the 3M spray glue. (theyre not that much $$) theres a few but ive used the aircraft something or other on my head liner.
2nd- carefully take the plastic trim from around the edges of the headliner. if you break one of the tabs on removal you can use good doubled sided sticky foam tape to hold the plastic pieces in place on re-assembly.
3rd- tape up newspaper on the inside of the windows so the overspray doesnt get on them. (unless your really good at aiming a spray can) or just remove the headliner and take it outside.
4th- spray the affected area in small incriments, let it sit a few min, then press the material onto the board. (repeat)
5th- put it back together and let it air out.
this is not very expensive and would take you no more then one day to do. or you can go the much easier and cheaper route and just rip the rest of the material down and paint it any color you wish.