Weld pins can also be used on areas that you can't get to the back of. A little less invasive than drilling holes that need to be welded shut. But you need a pin welder and slide hammer setup to use them. Please don't do like the picture in Jerry's link with holes around the edge of the dent. The outer perimeter (eventually) is what needs to be hammered down while pulling the depressed areas up.
What JonG said about patience is definitely important. Take it a little at a time.


Kevin
1951 Chevy 3100 work truck
Follow this saga in Project Journal
Photos
1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car)
Busting rust since the mid-60's
If you're smart enough to take it apart, you darn well better be smart enough to put it back together.