These are the notes for GoZync 3. Docs for the latest version of GoZync--GoZync 4--can be found here. GoZync 4 is a free upgrade and is highly recommended (hint: it's faster).
Do this by clicking "Reset" in the lower left of GoZyncMobile.
BUT, know that if you're using Field Level Merge under Zync Options, reset will cause you to perform a (slow) first sync on your next sync.