That sounds like a mess...
You flush the whole system and put back in the proper amount.
It is very bad to have too much oil in the system.
You do NOT flush 1. the compressor (you just empty it manually)
2. the expansion valve
3. the evaporator ( although some books say you do )
4. to do the condensor properly you may have to take it out of the vehicle and be able to rotate it.
5 . the Reciever/dryer ( you put in a new one )