Shut off the water at the faucet, turning the knob clockwise until tight.
Insert the male end of the hose into the female connector on the end of the sprinkler pipe. The connector twists counterclockwise to attach the two parts.
Connect the backflow preventer to the faucet, twisitng the rotating connector counterclockwise.
Attach the female end of the hose to the threads on the backflow connector, turning the coupler counterclockwise.
Twist all connections half a turn counterclockwise with pliers to seal the line and prevent leaks.