Mike, to do it correctly, you'll need a vaccuum pump to draw down the system (to clean any debris out of the system and check for leaks). My friend bought one from a pawn shop because they are nice to have around but if you don't want to do much AC work, take it to a shop. Billy Nelson's on Florida and Linebaugh (I think) has a great reputation for AC work.

Oh and the compressor oil goes into the system just like refridgerant, through a hose in the low side of the system. Problem is you need to know how much oil and refridgerant goes into the system. If you don't have any of the tools and capacities, it may be cheaper taking it to someone rather than screw it up or buy all the stuff you need.