How to restore individual files from TM backup after clean install?

My teenage daughter's Mac Mini (running OSX 10.8) was cluttered with all sorts of stuff, even unwanted and inappropriate popup windows when using Safari, and more. So I made a final TM backup. Then I did a clean install of Mavericks.

Now, I wanted to bring back individual files and folders from that TM backup, BUT...

• going to Migration Assistant, I realized that it would overwrite the clean install and bring back the clutter. This is no option.


• going to TM, I realized I wasn't able to select any of the snapshots from the timeline


• going to the external drive containing the TM backup with Finder, all folders within her "old" user-folder showed a small red stop-sign, which I learned is an issue with permissions. I wasn't able to restore manually.

What to do now?

I know I could restore the cluttered state and copy folders and files manually to an external drive, make another clean install of Mavericks, then copy manually from that external drive. This seems a lot of time and work to me.

Is there an easier way?