The door panel is simply clipped on. There might be a screw you need to take off on the door handle, but I cant remember. Just use a long flat-head screw driver to pry the door panel off, and then you can use your hands to ease the rest of the clips out. Be careful, those clips are old and very easy to break.
Carefully pull the felt door piece from the door. Works best if using a scew driver to draw a gap and then pulling with your hands, although, they do sell tools to pull the door off of the fitting. The felt door piece is held on by plastic push screws that can easily be damaged so be careful.
Removing a 1991 Chevrolet Silverado door panel is pretty simple. All you will need to do is to remove the screws holding the door panel in place.
If you are refering to the turn signal flasher, you have to remove the driver side lower dash panel. It is not hard to do, the flasher is located on the back of the fuse box. I have not tried to get to it without removing the panel, but it may be possible. There is also a retainign clip on the flasher that you have to remove to get the flasher out.
Remove door panel for access and investigation
Open the Driver's door and look at the side of the dash. Remove the side panel panel.
Depending on what fuse, but on the left side of the dash, when you open the driver door, is a lift off panel that will expose your fuses.
under your driver side dash. you may have to remove the kik panel
2003 Chevy silverado door panel removal diagram
Located on the left side under the hood with a lid labeled "Electrical" and immediately inside the driver door on the dash side panel. 2000 Chevy Silverado LT Ext Cab 4 dr 5.3L 4x4 Z71 Driver.
Using a screw driver, remove the screws and the clips in the door panel (some will be in the arm rest, too). Pull the panel gently, reach behind it and remove any wire connector carefully, then pull the panel off the rest of the way.
IT IS MOUNTED BY RIVETS. YOU MUST DRILL THEM OUT
Using a screw driver, remove the screws and the clips in the panel of the door and remove the panel gently. Remove any wiring connectors between the panel and the door, then remove the panel the rest of the way.
you have to pull the door panel and access from the inside, the lens doesnt come out from the exterior side of the door panel