All you really need is some hand tools; a prybar and jacks/stands.
I did it all on my back with the truck up in the air on stands. The biggest thing is that you don't HAVE to cut the downpipe if you don't want to; you'll just have to drop off the trans cross member and support the trans with a stand or another jack. Keep in mind if you do that you'll have to have more room for the complete downpipe to come down so you'll either want the truck on a lift; or higher in the air (probably 4feet from ground to frame?)