I just replaced the drivers side front door handle on my 2005 Chevy Silverado. I ordered the door hansle from a place on ebay for about $13. It was an exact match and was not too difficult to install.
I watched a few youtube videos on which bolts to remove and how to disconnect the locking mechanism. Overall, it took about an hour from start to finish but I was going slowly. The door panel was easy to take off and put back on. I used a 10mm socket and 10mm wrench (for the hard to reach places). It was pretty easy to do especially with the instruction videos.