If they are not torn, simply remove them, wash the wiper rubber with some good cleaner and a rag to get all of the dirt/grime off. After cleaned and dried, put a thin coat of Vaseline (petroleum jelly) on the rubber. This should not have build-up, just enough to make the whole rubber blade dark and soft. This includes the edge that touches the windshield. If you do this every few months they will stay like a new pair.