With the engine shut off, find the sloppy spot in the steering and then let go of the steering wheel.
Start the engine.
If the steering wheel twitches one way or the other, the valve body on the top of the steering box will need to be tapped towards the firewall or towards the front bumper. It'll probably only need to go a couple thousandths of an inch so take your time.
Loosen one of the two bolts then re-tighten it very lightly.
Do the same for the other bolt.
This will partially release the tension on the valve body thus allowing you to tap it gently up or down, depending on the direction of the twitching of the steering wheel.
If you go the wrong way, the twitching will get worse so just tap it in the other direction until you get to a point where the steering wheel doesn't twitch when you start the engine.
When you're satisfied with the results, tighten the two bolts.