1993 GMC Back Speakers

I have a 1993 GMC Pickup with extended cab. Factory radio and speakers. One of my back speakers stopped working. I took the pocket area that holds the ash tray out to get to the wires. I made small cuts into the wire and saw that I had voltage going through them with my meter. I can not figure out how to get all the plastic wall panels out to get to the speaker. It looks like one item is overlapping another and another and so on. Is there a secret to get to the speaker without taking all the way up to the dash out? It even looks as if part of the roof has to come off.

i have had to replace that speaker on my drivers side. it is hard, the roof panel above the back window has to come out, take seatbelt off of top, and the armrest with the ashtray will have to come out. when u fold the seat down that plastic has to come off. it takes a long time and is a pain