The center trim panel gets broken a LOT due to the design......... There are 2 studs mounted on the back of the panel, and 2 respective nuts that hold it into the steel dash frame..the studs are to the right and left of the control area.
If you choose to go in from the bottom, as you probably know, it all has to come out.......the ashtray and frame, the radio and brackets, then the control...........you can get the studs by carefully standing on your head, twisting your back out of wack, and asking your wife for the Ibuprofen.
Be CAREFUL when unplugging the vacuum line cluster from the control before you remove it........they tend to get brittle from heat, and can break easily............wiggle it gently and easily until it comes off..........it's also a LOT easier to change the control if you first remove the glove box door and then the liner. This gives you wide open spaces to work on removing the cable for the heat control, and taking everything out by SIGHT instead of going in blind.
Good luck.
