I slammed into a concrete pole in a '72 Buick when I was a kid...going backwards. (Note: always check behind you before attempting a Rockford!) Bent the rear section of the frame rail up, kinked the tops of both quarters and pushed the back of the car forward a bit.
We pulled out what was left of the tail lights, removed the restyled bumper, and put a 6x6 block of wook into the trunk, running chains from it to the hitch on my dad's Dodge van. Blocked wheels on the Buick and pulled until the trunk floor was flat again, and most of the kinks came out of the quarters. Then I hammered the tail light area mostly flat again.
For the frame, we took my Craftsman floor jack, wrapped the chain around the portion that was bent up, and then down to the jack. We situated the jack so the pad was under the portion of the frame that was still straight. We then lifted the car with the jack, but the chain was holding the bent portion of it, having the effect of pully the bent portion back down in line with the rest of the frame.
Chain the truck down to the floor (if you can...concrete lag bolts in the garage floor?) or work up something like I just described, and jack the front of the frame back into place. If it truely is just the front portion of the frame rail, ahead of the cross member, you should be able to handle that at home, and it'll be really simple. Just throw the chain around the good portion of the frame, run it to the jack, and start lifting the bent part back up. You could also get a 6x6 and put it under the frame rail (front to back), chain the unbent portion of the frame to the 6x6, set a bottle jack one the 6x6, and jack up the bent portion. The bottle will try to lift the truck, but the truck is chained to the base of the bottle, so the portion of the frame the bottle's ram is contacting should push up.
-Brad
