If you are not 100% positive how to merge posts please read the following.
So you have found a post or thread that needs to be merged into another thread. They are located in the same Forum (#1 in the pictures)
1) To determine the post which needs to be moved Look at the Post date or Post # (#2 in the pictures) of the first post in each thread. Always move the newest post (highest Post#) into the older (lowest Post#)
The post above is numbered 2438651
2) The post above is the oldest of the two posts. Copy the post number, you will need it in step 4. The post number is 1914356
3) at the newest post click “Manage Topic” then “move/merge this topic”
4) Use the post# that you copied in step 2 and place it in the input box and check the dot then click “submit”