Help transfering files to a new domain name

[pythonimp]

Hey guys, this is my issue.

I've got a forum with 11k members on it. But the domain completely attacks another forum i'm competing with. I came to an agreement with the other forum that I would change my domain name and we could work together.

Well I bought the new domain name, and just wanted to transfer EVERYTHING from my old domain to the new one.

Well I tried that, I went into the config and changed the filepath, and left the DB the same, moved all the files over and it did not work..

How can I put the old forum on the new domain without losing users/posts/mods/etc?

Any and all help would be amazing guys!

Thanks a lot!

*EDIT*
Note all of the files and domains are on the same server. I do not want to change servers. I just simply want to move to another domain. I tried copy and paste and changing the config.php but using the same DB, and it did not work.

Any thing guys?