Deleting unwanted categories

I'm trying to modify my ads module to be tailored for my site, but I can't seem to delete unwanted categories, and cannot find a post on it relating to 7.1. Is there a simple way around it, or is the only option to go into the code to delete them?

admin panel >> settings >> Categories Settings

look for ads and remove categories as required

Thanks, went there but Ads doesn't show up in the drop down menu. It starts with Articles.

 Admin Panel >> Modules >> Ads

browse down page and click 'category manager'

should work :)

Yeah...that's where I started, lol. Think it could be a database error? It just tells me deletion failed or it simply returns when I go back.

Well whaddaya know? It comes back in the backend, but has been removed from the site...thanks for your help tho.