Here is a good instructional video on how to remove a Challenger's door panel. It comes in handy if you have to replace cracked plastic window/door trim (like me), install a new power window motor, or a new radio speaker. Dodge Challenger Door Panel Removal - YouTube
I have found that it is possible to replace the door/window trim without the complication of removing the door panel. The trim piece, held in place with hidden staples, can be removed by using a nylon pry tool. Just pry downward and the staples will pop out. After you remove the trim, use flexible E6000 glue (sold in craft stores) to keep it in place- not staples. Attached are a few installation photos. The trim piece kit can be purchased at any Dodge Parts counters for about $10 (for two). The MOPAR part number is: 68071960AA.