Hi Carlos,
You can watch them as many times as you want. Also, when we update modules for new versions of ClearPass, you can go back and "re-watch" the modules we updated and see the new content.
For example, when CP 6.2 training is released (we're skipping 6.1), we'll post here on Airheads that for people who bought v6.0, go back and re-watch modules 1, 4.2, 8, and 10 (or whatever) as those modules have new content. You'll then go into "My Profile" on the LMS, find those modules, and launch them and you'll see the 6.2 content.