How Can I Slim My Arms?

so prom season is upon us and all the dresses i seem to like are either strapless or sleeveless im not skinny im actually pretty chubby but im not worried about my torso area i was wondering if it was possible to just slim/tone down my arms or will i need to go on a full on diet to do this can i accomplish this with like one of those shake weight things or idk any ideas? any answers? any suggestions? they'd help thank chuu <3