Replacing Door Light Switch

[11555wally]

Have an 86 C10 and wanted to check out the door switch that controls the courtesy lights and not sure how to access the back of the switch. Lights door come on when door is opened. There is a fiber panel below the door post area that is held on by push in plastic fasteners and that didn't show me anything. There is a small panel (approx. 3 x 6) that is held on to the inner fender that when unbolted doesn't seem to want to come off. Don't want to force it. Was wondering if anyone has accessed the switch and can tell me how. Thanks in advance.