You can adjust by feel or adjust to spec as Army did. Adjusting by feel is a good way to wear out what's left of a steering box's life. As Army pointed out, it's not as cut and dry as adjusting to the point of no play then backing off, as some do with wheel bearings.

That said, it's a lot of work to take a very worn box apart for a simple adjustment. Back off the adjustment screw in eighth-of-a-turn increments keeping in mind that you don't want to go too far. An inch of steering wheel play will feel like heaven at this point. Note that adjustments should be made with the front wheels pointed straight ahead. It's normal, I was told, for more play with the wheels turned.

Sixto
87 300D