OMG. what a bunch of wrong information. Converting is not rocket science, and actually almost anyone can do it. But you need the correct info, which is not in this thread.
My qualifications: I am certified HVAC tech in both automotive and non automotive (section 608 and 609). Have been doing A/c work for over 45 years. Everything from small refrigerators to multiple hundred ton industrial chillers, plus auto and transport refrigeration.