How to merge Threads

To Merge a Topic

You can either click the merge button above your quick mod tools or select 'merge topics' from the quick mod tools drop down menu. The next page will tell you the title of the topic you have chosen to merge. Click the 'select' button. You can then choose the forum of the topic you want to merge with, using the upper right hand drop down menu and check the topic that you want to merge with. The next page will again show you the topic you want to merge and now the topic you want to merge with. Click send.

Posting & thread Guide
http://help.forumotion.com/frequently-asked-questions-f5/guide-to-mod-tools-t10773.htm