wire wheel & grinder, scrapers, pointed screwdrivers, whatever will work
for a good sealer, use urethane based. much better than solvent base, will stay on better & pliable way longer.
i just did the entire cab on my crew, used this stuff, 'bout $10 a tube. i primed everything before i sealed it
http://www.proformproducts.com/en/pr...32&category=24