TortoiseHG switch back to a closed branch

Please can someone guide me through a process here? I'm a bit of a newb in Mercurial so I'll post a pic to be more specific.

Here's the tree of our repo right now:

enter image description here

We have 2 branches: processors and extra libraries. We created extra libraries after processors to test certain issues. Then we closed it and continue working on processors.

Now it occurred the need to change back to extra libraries in #645 to push some new stuff for testing. Is this possible now? and how can I do it with TortoiseHG?

Thanks in advance!

PS: Sorry for the silly question but I want to be very careful on this repo..

Solution

Closed branch is usual branch, which just have some additional meta-info in branch-head.

If you want to "reopen" closed branch, you have

Update to head's changeset (645)
So some (needed) changes in working dir and commit: changeset 658 will be new head of active named branch, tip of repository and closed named branch will become open