So all of you was wondering if there is an Mybb Forum guide then here it is now 
ehehhe
Content In This Guide
--> How To Change Footer Text
-->How To Customize Mybb Forum Theme ? Here
--> Fixing Database Error ? Here
--> Error Codes And How To Fix Them ? Here
[More To Be Added]
Then click "Footer Templates"
Then click expand
Then there should be a link called Footer click footer.
Then find <div id="footer"> you should then see all the mybb group stuff and just edit it the way you want it.
This Guide Solution Are Taken From MYBB Community :)