Please advise:
where and how can I change the name of an already existing "Theme"?
I want to change the name ("Tools for OC:23") to another name.
Thanks in advance.

My forum: https://czsktym-skichallenge.slovakforum.net/

We don't have access to see your forum. We have to register first. Can you explain me where is that "theme" name?

I unlocked the forum - check here

I don't know if it is enough to show like this, or if some other explanation is needed.

This is the title of the topic in Slovak: "Pomôcky pre OC:23" and I want (need) to change this name.

starec wrote:I unlocked the forum - check here

I don't know if it is enough to show like this, or if some other explanation is needed.

This is the title of the topic in Slovak: "Pomôcky pre OC:23" and I want (need) to change this name.

Oh, you want to change the name of the topic. Just click Edit button on the forum and you will see on the top you can retype new title

Do you mean the name of a category or forum/sub-forum?  If yes, you edit the title in the same place where you create and delete them in the AP.