Headlight adjustment for 1997 Riv

New front struts and springs were installed last year on the Riv. The original springs were replaced to give the front end a more upright posture. That came out fine. Now apparently the headlights are aimed too high. I'd like to adjust using the front wall of the garage, which is drywall. What are the specs? at what optimum distance from the wall should they be adjusted? and what is the best (or easiest) procedure?

-edwinn