Just did two GM doors, One for a lock cylinder and the other latch.
You need an assortment of "special tools" that make the job easier. The flat forked "panel popper" is a snap on tool. A 90 degree bent screwdriver ( make this one ). A retaining ring compression pliers ( made this one ). 9/32 nut driver. 1/4" pop rivets and gun.
First and formost is proceedure. One of the doors I just did was on a Tahoe. The lock mechanizum, arm rest bracket and lower guide panel are all pop riveted in place. Make sure you have enough rivets to completely replace them. They are aluminum, use aluminum replacements.
So, you unbolt the two bolts ar the arm rest and the beauty ring around the door controls. Remove the door mirror access panel, it will be either a screw or snaps. Be careful of the wires, three connections; speakers, door controls and light. All unplug except the light. It is easier to just remove the entire lamp and socket assembly.
Use the flat fork to pop the white hold downs out. Chances are you will pop a few out of the steel, thats okay, they can be undone. Start poping at the bottom and swing the door panel out from the bottom without lifting.
Once you have it out and the white hold downs are unpluged, wires disconnected, you can lift gently until the top separates from the window channel. Set the panel aside.
The motor will be in the lower right hand area and I find it easier to work on if the window is up.
I hope this helps.
