Once you're in position where you want to dig, engage wheels so they work together. Put the throttle up, throw lever to start the chain and auger spinning, and lower the bar into the earth.
The trencher will start digging.
Lower it to the depth you want, usually all the way down. Note: This could take a few minutes, according to how far down you want to dig.
The auger will push dirt off to the side.
Keep the gas on full throttle and control the speed by using the transmission control.