heater coil/ ac parts

If I remember right you don't but the bolt can be tricky to get at mine is a 74 though not sure how much they differ but it work sort of like 2 seperate systems the heater core portion of the box can be removed completely seperate of the condensor. You should be able to look at the firewall to see where each part is I believe the heater core is to the middle of the car and then look at the box they are fairly simple but just for the sake of add stress you might want to consider pulling the glovebox and maybe the radio or a/c controls for easier access and line of sight be careful when you remove the vacuum fittings from the controler they are plastic and can be brittle