You'll need a good set of heavy duty circlip pliers, a copper or dead blow hammer, some WD40 or similar an a whole lot of patience. Some optional extras to help make the job a lot easier would include a bench with a vice attached, a couple of small flat head screwdrivers, a decent set of wide and pin nose pliers and most of all a good sense of humour.
Assuming you already have the turbo off of the car, it's a case of removing the actuator, removing the circlip that holds the compressor housing on, tapping the housing off with a soft hammer, removing the locating dowel and then reinstalling everything with the compressor housing positioned where you want it to be. It sounds simple enough, but getting the circlip out and back in again can be a right pain in the arse. You'll also need to come up with a way of reattaching the actuator bracket after the housing has been rotated, unless your using an external wastegate.