Got a Question

i was out working on taking a few parts off my new jeep when i looked at the front fender and door and they were looking kinda funky...i took a screw driver to the fender and began to scrape off the paint when i found a shit load of bondo. im going to replace the fenders and hood, but what do i do about the rear? what is the best way to get it down to bare metal so i can fix the dents or rust?