I read somewhere that acetone would dissolve the glue that held the glitter on, but you'd probably want to test it on a small spot first to see if it also took out any dye.
Also wanted to note that glitter is considered a microparticle that our water treatment systems aren't equipped to filter out, and it is one of the tiny particles that is poisoning our oceans. Definitely not a judgment on you or your purchase, but was merely something I hadn't considered until recently.