Find the name you want to revoke and simply delete it.
1. Sign on as administer, this will take you to your admin page
2. Under the sharing section, there is a link to your invitations.
2. Click on Send Invitations.
3. You should see a list of everyone that is invited.
4. Stroll down until you see the person you want to delete.
5. There is a drop-down box to the left of the person, click on that box.
6. You will see four options; click on the option you want to do.
7. then scroll down to the bottom of that page and click on save changes.