drain out 5k2 excess grease

when met this problem:
if grease was added too much than compressor needed, it will cause hard working and overload current to cause the restart switch to off,
operation:
Don't connect with any tank , or unplug the hose , unscrew the burst disc valve, turn on compressor - start , keep it running over 2 hours.
when grease come out from the two valve, clean it.