Like Debra wrote--this isn't really multiple versions--it's multiple windows
looking at the same workbook.

So once you open the workbook, you can unhide as many windows as you need to
via window|unhide.

Then you can do Window|arrange|tiled to see all the windows.

Select the window you don't want and hit ctrl-w to close that window.

When all the colon/Numbers are gone from the titlebar, you're done.

Then save that workbook while it's visible and doesn't have multiple windows
open.