Don't use that cr ap. If you need to re caulk anything on the sides, scrape out the old caulk unless it's not in the way of new. Clean it up good, get all the old off the surfaces with a razor knife and wipe it down with solvent to clean it up, like lacquer thinner.
Use a good urethane caulk, not silicone. Like Sika flex or dicor? Whatever the rv shop Reccomends. You're not going to find what you need at the Homie Depot.
Use the smallest bead possible. Takes a little skill to caulk well and it shouldnt include using your finger as a putty knife everywhere.
Oh and don't use flex seal as seen on tv!