How do I remove a thread from a folder?

What you are referring to are tags. Currently, after the latest A2K update, there is no way to delete our own tags and you can never delete the tags someone else has applied. What you can do is add more tags of your own in an effort to replace a tag you dislike.

Can someone please help me with this thread?:

http://able2know.org/topic/168006-1

I put too many of the wrong tags on it.

What tags would be the correct ones? Give a list and I'll help you add them.

Race would be a good one to add. So would Society.