Unfortunately, I couldn’t find a direct way to upgrade to Enterprise Edition, the only way was by removing and re-installing the Exchange 2010 again.
You’ll get somthing like this under Hub Transport Role removal:
“Couldn’t open package ‘C:Program FilesMicrosoftExchange ServerV14MailboxMSFTE.MSI’
1st make sure nothing is being moved from one server to another in the same Exchange organization
2nd go to Programs and Features, select View Installed Updates from the left menu
3rd, remove the Update Rollup3 for Exchange 2010
This will take a while, it’s ok, don’t kill the process.
Finally, try the removal again, and it should work fine.
Sometimes, that might not work, you’ll need then to remove the Mailbox Role only, reboot the system, then remove the HUB and CAS roles.