Backup/move problems

Hej php fusion people

I have had a problem with transfering a homepage form one domain to an other, the situation is a follows:

I have a php fusion homepage on impure.dk

I wanted to move all the posts user etc from that place to impuritygaming.com/nerdrage

I have read many ways to move it using phpmyadmin, somthing called big dump (or something like that) and lastly i thought i could use the backup ability form within php fusion form the admin panel

I tried the backup ability and it worked on a homepage that i had already called impuritygaming.com/vigilance, and it worked, so i wanted to do the samce for impuritygaming.com/nerdrage and ofcause it didn´t work there...

I then changed the name of vigilance to nerdrage and then wanted to update the place, and well i didn´t do it right so with my smll knowledge had to delete that homepage, so now i´m back to the core of the problem

How can i move info, forum posts users etc from impure.dk to impuritygaming.com/nerdrage

step by step would be nice since I´m no hardcore coder or anything.

thanks in advance