The Test Repository module can be found in the Lead's Desktop, Tester's Desktop and any other role's Desktop that has been given access. On selecting a testcase in the local tree, a user can begin to edit. A testcase will always start at version 1 and any modifications saved to the testcase will increment the version. During this editing process, a user may determine that they wish to revert back to a previous iteration of the testcase. This can be done easily using the Testcase Versions feature.
In a testcase, open the Testcase Versions window by selecting the Versions button just above Priority. This brings a window that immediately shows the user all versions of this testcase, basic version details, and which version is the current one.
Selecting any of these versions will expand the window and show the testcase and all it's details, steps, attachments, etc. as of the time of that version's creation. If you decide you want to change the current version of a testcase to another one, all the user needs to do is select Use This Version and the testcase will be modified automatically with the details of the testcase for the version selected. From then on, all users will be able to see that version when viewing the testcase. At any time, the version can be changed or reverted as long as the version is selectable.