Using the revert action
If you checked out the wrong topic or you wish to start over, you can choose to discard all changes and revert to the previously-saved version instead of checking in an object.
If you have a topic or map checked-out (depending on your privileges), a Revert button appears for that content object on the My Assignments page and either the Map Editor or Topic Editor, for maps and topics respectively.
Reverting enables you to discard your most recent work on the topic or map, and restores it to the version when it was last checked in.
To revert a selected topic or map: