How to run older version

I moved to a new server while running v6 then I upgraded to v8. I just realized I missed moving one of my v6 projects to the new server.

Now on the new server I need to run V6 (instead of the v8) in order to import the old v6 project. Then I should be able to convert it to v8.

If my default version is V8, how can I run v6?

thanks in advance.