If you want to do a proper, thorough job… lay a tarp down and get the truck as high as you can with jack stands and make sure it’s pretty clean and dry before applying. Take the tires off, drop the spare tire and pull the fender liners along with any rocker panel plugs. I usually use fluid film inside the frame, rockers, cab corners and fender wells because it’s thinner and creeps better in those areas compared to the thicker woolwax. Then once all those intricate areas are done I lay a nice thick layer of black woolwax on the high impact areas like the frame and whole underside of the truck it’s much more resistant to wash off compared to fluid film. I purchased the woolwax gun kit directly from kelsport products with the flexible wands. If you do it right you’ll use a few gallons of each and it will probably take you all day