My 2014 Challenger SXT with stock suspension only needed one bolt on the right side. Got my right front wheel from -1.5 to -1.3. According to the instructions, you only need TWO screws (1 per side) if fall is your only concern. If you also have a caster problem, you may need four. Also in my case I only needed one. This adjustment can be made at home, but note that the original forearm screw uses a 12mm hex head. So make sure you have a 12mm hex head, or use a 12mm bolt with a lock nut like I did. .