Heat gun or blow dryer to heat them up and then they'll come off pretty easily.
Interesting that this thread came up today. I'll be stripping off stickers on my new plastics tomorrow.
Good Luck
The best solution I have used for years is Goof Off. Go to Home Depot, ask someone where the Goof Off is. You won't regret it! It's awesome stuff! I took my stickers off in about 10 minutes flat (all stickers on a brand new bike). No damage to the paint.
Welcome to the Goof Off Website
is difficult to remove the " S " on the tank ???
Not really, it seemed to be held on with a automotive type 3m foam tape, just get en edge of it with a finger nail and slowly peel it off, mine broke off in a couple parts but the 3m type gray foam adhesive tape just rolls up under the pressure of a finger rubbed on it. Came off easy and then followed up with Goof Off and then a coat of wax.