My expierience hasn't been too great. I usually have made a mess and been more dis-satisfied with the results than if I had left them alone. I have had decent success with removing them VERY, VERY slowly taking extreme care not to stretch the graphics. The clean the area where they are to be re-applied very thouroughly and then spraying the area to be re-applied with 3M spray adhesive. Bonus to buying the spray adhesive is that is also works well for me as a grip glue too.
Good luck if you decide to try, I have had limited decent success with re-applying them. Maybe someone with better success or ideas will chime in soon.
Moteaux