Are you going from Windows VMPro to the Linux VMPro? If so, I just did this with 8.0 and it went very well. Hopefully this all still applies with 7.
Copy the Accounts and Greetings folders, then run these commands in powershell from the backup folders. These should get the file names to match properly. we are prepending a period to the text files and making them all lower case. We also need to make all the greetings are lower case.
Get-ChildItem -recurse -force | Where-Object { $_.Extension -eq ".TXT"} | rename-item -newname {"." + $_.Name.ToLower()}
Get-ChildItem -recurse -force | Where-Object { $_.Extension -eq ".WAV"} | rename-item -newname {$_.Name.ToLower()}
Make sure all your user accounts have had their mailboxes created in server edition. Stop VMPro and copy the modified files over and replace. You will have to enable root in /etc/ssh/sshd_config and restart the sshd service to using WINSCP to copy and replace files.