Backup the existing translations, to an FTP server or the Flash card (or both to be safe)
Install the CM 5.2.1 CD, start from scratch and reload the server. During the reloading of CM 5.2.1, you will be asked if you want to install CMM (move the cursor down and place an X on that line)
Once CM 5 is loaded, and you have setup all of the passwords, IP address's, gone through "configure server", loaded your CM5 license and password file, you can them "resotre" the CM4 transaltions, and then start working on getting the CMM working (follow the documentation to setup the H323 trunk group, signalling, etc)
P.S. Don't forget you will also need to upgrade the SAMP firmware, I would suggest you do that first...
Mitch
AVAYA Certified Expert