Usually there would be a nut with a screw driver slot in the middle of the nut on top near center of the box. Loosen this nut and while holding the nut steady turn in the adjusting screw clockwise while wiggling the steering wheel back and forth until desired amount of play is reached. Do not remove all of the play otherwise you will find yourself constantly correcting the steering left and right while driving. Then tighten the nut while holding the adjusting screw in place and that should be it.

