Jerry,
You do NOT have to remove the door panel and mirror just to replace the glass. The link shows you how tor replace the factory mirrors with Muth mirrors.
If the mirror housing is OK, and just the glass is broken, you can buy the mirror glass with the plastic backing frame already attached for about $20 (that's about what it cost for my Toyota), and you can just pop the mirror on in less than 2 minutes and no tools are required!! Why would you want to pay someone $40 just to do that??
...Rich