Yeah all you really need is a hammer, and something to cut metal with, and a welder(preferebly mig with gas). And like marshal said, get some autobody dollies.. so you can form the metal with the hammer. May take a bit of time if you haven't done it before but you will find that it is fairly easy. You should know this but once you have everything cut out and formed, ready to weld in, tack it in with like 6 tack welds, then go around the piece and just keep tacking it. Try to go from one end to another cause thin metal warps easy when it's hot. Then once you have a good portion of it tacked in you can do probably about 1/4" - 1/2" welds. Desireably you want to let it cool between welds, but for that piece I'm sure you won't have to be too anal about that.