Turn off power to the unit at the thermostat and breaker
Remove the access panel or grille
Clear away loose debris from the coils
Use a soft brush or vacuum with a brush attachment to remove dust
Spray the coils with a no-rinse condenser coil cleaner
Let the cleaner sit for the recommended time
Rinse the coils gently with low-pressure water if required
Clean the surrounding area and drain pan
Straighten any bent coil fins with a fin comb
Reinstall the access panel or grille
Restore power to the unit
Check that the system is running properly