Move forum to new URL

hello.   I am looking to merge my current phpbb3 forum on one site to a MyBB forum on a new url i purchased.   What complications should i expect and how should i go about this?   

I used the search bar to little avail.   

Do i need install mybb on the current site then merge then move that db to the new site?  or can i preform half the merge and move the merger to the other url?