Date registered: Jun 2005
Vehicle: 86 190E 2.3L 16V, 93 400E, 95 320TE, 98 S500
Location: Seminole, FL
Mentioned: 3 Post(s)
Quoted: 499 Post(s)
Converting an R12 system to 134a isn't a hard job if you have the correct tools and know how. The AC system works under a vacuum and you'll need to extract any remaining refrigerant in it. Once you've emptied the system, you need to change the valves over, flush the system, changed the expansion valve, change the receiver dryer and then draw the system down before introducing the new refrigerant and oil.
If you don't have the necessary tools and equipment to do this, there is no way it's a DIY job. Take it to a professional shop