You need to remove the interior door panel. Once that's off, the replacement of the handle is fairly self explanatory.
Here's a speaker install guide which includes info on how to remove the door panel.
http://rayrayonline.bravehost.com/frontspeaker1.htm
The only part I disagree with on the removal is the part on page 2 where he says to
"Pop the black triangular thingy by the side view mirror out. They are held in by 3 clips. "
That black triangular piece doesn't need to be removed and it's easy to break so I'd just leave it alone.