Pull vacuum and disconnect the pump so there is vacuum in the a/c system. Drive the vehicle for a day or so to get things good and hot (aiding evap of any liquid water), and shake things up a bit. While things are hot, reconnect the pump and draw vacuum again.
Remember that the dryer/accumulater, if the desicant (an internal bag of water absorbing crystals) is in good condition, will suck up any remaining water vapor moving in the system.
Commercial A/C shops reqiure a new dryer/accumlator anytime the system is has a significant repair (replacment of a hose, pipe, evaporator, condensor, or compressor). This way they can pull vacuum one time to evacuate the unwanteds and make sure the system doesn't leak, and let the desicant do the rest.