You normally rewind cameras to remove exposed film. On an XG-A, there is a small button on the base plate (bottom of camera) which releases the sprocket drive and allows you to rewind the film back into the cassette using the "flip out" rewind button (top right, in above picture).

Here's the manual, which identifies all the parts:
http://www.cameramanuals.org/minolta_pdf/minolta_xg-a.pdf

An ME is broadly similar.... I doubt either is broken - they are a fairly solid build.

Hope this helps