Is there any non-destructive way to remove deteriorated roof gutter-sealant -Ford Van- in order to remove rust and reseal against water leaking into the interior of the vehicle?

There is a non-destructive way to fix a roof gutter on a Ford Van in order to reseal against water leaking into the interior of the vehicle. Wherever there is a rust hole, a person can use a product called Bondo. Bondo is a tape or screen that is fastened on using a glue. Then sand smooth, after it dries. If there is still a leak, a new sealant can be put over the old sealant just to fill in holes. After this dries, it can be sanded and sprayed with a primer paint.