use a heat gun or a blow dryer to soften up the decals, they'll come off pretty easy. to get off any glue residue, use spray polish. spray it on REAL thick, let it sit for a few seconds, and it'll wipe right off, and won't hurt the paint any.

and btw ALL honda's (and most every other modern bike on the planet) have the tank decals under the clearcoat. it's to keep them from peeling if/when you spill gas on them.