I was just wondering how do I change my topic's description? Thanks in advance!

If you have already posted a topic, and want to change your topic's description, you will have to click the "Edit" button (bottom-right of your post) and select "Full Edit".
It will load the topic so that you are able to edit the Topic Title, Topic Description, Topic Icon, etc. =]

If you have any trouble doing this, please let me know.

I found it, thanks for your help!