Dropping the tank is pretty easy if you don't have too much gas in it. Look up some of the " how to convert a 15 gal tank to 19 gal " threads and they go through it step by step.
I think all you will need is a floor jack to lower the tank once it is free and a socket set with a few long extentions to get all of the bolts off of the skid
You have to unhook the fuel line, the wire plug, and the filler tube.
For me it was harder to get the tank lined up when putting it back on, but that wasn't too bad.