Best way to do this that I have found is to get some dental floss and run it behind the decal (preferrably on a hot day so the glue is more pliable) then if need be find a paint safe glue solvent... can't remember the name of the one i use and it will take off 99% of the glue residue. finally go spend $20 on a clay bar kit and clay bar the car to get the last bit of residue from the decal off...

in the end you won't even be able to tell there was ever a decal there.

edit: p.s. welcome to the forum i hope you love your car as much as the rest of us love ours.