Cutting it will leave a bare metal edge and tye will require paint or it will rust.
The least damaging to paint will be a hack saw at said above. A jigsaw with a metal cutting blade works too. Make sure you use tape to protect the paint from the foot of the saw.

If you are lucky you just may get away with touching up the edge with paint.

Good luck have fun and take your time. A rush job will disappoint.

I have no faith in human perfectability. I think that human exertion will have no appreciable effect upon humanity. Man is now only more active - not more happy - nor more wise, than he was 6000 years ago. Edgar Allan Poe