Tom...the only way I have been able to do that is to sand with 320/400 wet /dry paper. However , you have to be careful not to sand into the base. If the clear is peeling to the base then you will have to rebase. I always use a good wax/grease remover after sanding and just before painting. You can also wash the paint with soap and water, but I prefer the wax/grease remover...good luck...Jim