I adjusted mine by mounting a pointer on the dash in front of the steering wheel so that it was close to, but not touching, the steering wheel. Then I took the coach out for a drive on a good straight road, without too much crown.
Holding the wheel in the position where it tracked straight, I then put a mark on the steering wheel that aligned with the pointer.
When I got back home I used the front jacks to raise the front wheels off of the ground. Once off of the ground, and properly supported, I adjusted the Safe-T-Plus so that the mark on the steering wheel was in line with the pointer. That was it and 50,000 miles later it is still working great.