Board Thread:Site Questions/@comment-26444017-20180703003643/@comment-10502460-20180703185704

Dr. Frank N. Furter wrote: I believe only an admin can do that, so you'll have to request it.

Hope this helps.

That's false. I close my workshop threads all the time when I'm done with them.

Hover your cursor over the bottom section of your thread OP. A tab will appear that says "options". Click that, and there will be a dropdown menu, with an option for "remove". Of course you can only do this if you are the OP or an admin.