yup, just leave in the sun for a while. if need be use a hairdryer but keep the dryer moving, don't let it blister the paint.They're wicked easy to peel off. Just park your bike in the sun, wait 5 minutes and start peeling.
It's the frame and tank stickers that suck balls.
NO GOO GONEany left over glue, use goo gone
most aftermarket decals are overlays anyhow so you can just leave the original and apply the new one over the old and use the old as a template on where to place the new one.