I assume you mean a long step to a short step (if I'm looking at your avatar correctly)? If so, I have never seen it done - only fleetsides. The process should be ABOUT the same, at least the frame cutting - and you'd have to take all your removal section from in front of the fenders I believe. A great series on the show TRUCKS! did this on a fleetside - here's a link to the show if you wanted to buy it:
http://www.powerblockswag.com/Trucks...hevyc10dvd.htm
Or you might brows the powerblock tv site a bit more and find just the single episode about slicing the bed and buy that rather than the whole truck build dvd.