This is not a simple project. I did it to resolve a squeak overhead and to add insulation.
You have to remove the panels behind the seats. The driver side is easy to remove in my unit 37ts. Passenger side was a little more difficult due to small cabinet.
Then you have to pull the trim and staples on the floor of the overhead bunk. To do this i used a large flat crown bar and just started to pry it up. You will have to fill these holes with filler and refinish after the project is done
Once the floor is up you can remove the staples ondraw thremovede pleather taped foam protection pad. Once this pad is you with see the head liner is stabled to the side of the opening. Then remove the plastic trim in the cab which is golden the liner up. Finally the line is stabled to the headliner material running from the ceiling to the floor behind each seat.
Then the reverse. Probably takes two hours to remove. 2-3 to replace and another 2-3 to refinish the wood floor of the bunk.
You will need a power stapler to resecure the liner material and attach the wood deck.