1. So as always the first step whenever doing a refrigeration repair, is to recover all the Freon out of the system.
Hook up your digital gauges, recovery tank and recovery machine to the air conditioner.
Now make sure all your ports, nobs and dials are open so refrigerant starts flowing into the recovery tank.
Turn on your recovery machine and let it pull all the Freon out until your suction pressure is down to 0 psi.