I'm still running duracool in mine. but if you want to run 134A a good set of gauges and a vacuum pump you can DIY
134A
88479 FREON GAS, AIR CONDITIONER (DRUM, COOLER REFRIGERANT) 90986-02007 250G, AIR CONDITIONER(DEALER OPTION) 90986-02008 200G, AIR CONDITIONER(DEALER OPTION)
Thanks.
Yeah, I know. I would be confident going that route if I knew that the system was empty, but since it is full and working fine, I prefer to go somewhere that can recover the freon.