carefully cut the lock hole out of the backing paper w/ razor blade, this will help you line up decal.
use water w/ some dawn or similar dishwashing soap.
clean panel, spray w/soap
apply decal, while wet and you should be able to move it and line it up if needed. squegee water from decal with plastic knife (ones for bodywork-bondo work well)
you can let it dry with top paper on and remove when dry.
be careful removeing top paper and watch to insure decal stays where you want it.
Hair drier/ heat gun a nice afternoon and sore fingertips.
Other route some body supply stores have soft rubber wheels for a drill that will actually rub it off for you but I 've never used one personally,.
Usually the hair drier and once again that plastic body filler knife and the good old five digit tools are the way I go.
it's all just a little time to do it right.
would highly suggest not useing a razor blade for the factory decals are thin and you WILL get into the paint if you were to try it, and it is a PIA to get the panel straight after that...