You will need a recovery bag (or appropriate recovery tank).
Below is a picture of the recovery bag attached.
You will need a floor fan to keep any refrigerant away from the work area, (remember the R600 is heavier than air and will settle at the lowest point).
The R600 is Flammable, so, place a fire extinguisher nearby so you can reach it if needed.
Discharge any capacitors.
Once you have attached the gauge
set to the unit and to the recovery bag, the bag will begin to fill. Bump the
compressor several times to release the refrigerant from the compressor oil.
After a full evacuation, approximately 10 minutes, you can take the bag outside
and release it away from potential ignition sources. The R600 is heavier than
air and will sink to the floor or ground. This is why its recommended to have a
fan at floor level blowing any R600 away from the work area.