BizTalk Server Evaluation Version Upgrade to Full Version

One of my customers had installed an evaulation version of BizTalk Server 2009 for their test environment, and sure enough the version expired and BizTalk stopped working.
So they needed me to upgrade it to the full version (in this case we used the Developer Edition but the same process is used for upgrading to Standard or Enterprise Editions).
But when I started the Install process it immediatley gave the message that you can't upgrade the evaluation version and you must uninstall and reinstall.
At first sight this looks disastrous but infact you can recover everything because unsinstall does not delete the Biztalk databases. But there are a number of steps you should take before uninstalling BizTalk.

1. Export the applications to MSI files and Export the Bindings just in case it all goes horribly wrong.

2. Make a screen shot of the host instances in BizTalk Administration because these will be deleted and you will need to recreate them.

3. The host instances use service accounts and you'll need the passwords for these accounts.

4. Ensure that the account you are going to use to install BizTalk is the same one you used for the Evaluation version. If like me you don't know, use an account who is a local administrator and is sysadmin on the SQL Server box where the databases are installed (dbowner of all the BizTalk databases may be enough).

5. Make sure you have a copy of the BTSNTSVC.exe.config file as this may contain configuration settings.

6. Have a backup of the Enterprise Single Sign-On secret - and you must know what the password is (ideally the password hint will help). This is vital. If you don't have the password for the backup you will be hosed. I don't know if you are able to do the backup once the evalaution has expired. If you can open a command window and navigate to c:\Program Files\Common Files\Enterprise Single Sign-On. Then use
ssoconfig –backupSecret backupfilename

OK, now you can uninstall the evaluation version and install the full version. Next you need to run the BizTalk Configuration wizard. Be sure to select Custom configuration and enter the database server name and the account credentials for services.
The Enterprise SSO option is currently configured so select Join an existing SSO system. You will get a warning symbol indicating you may need to restore the SSO master secret (you will definitely need to).
On the Group otion select Join an existing BizTalk Group. On the BizTalk Server RunTime do not Create In-Process Host and Instance because In-Process Host is still present. Liekwise do not create Isolated Host and Instance.
Configure the other options appropriately and Apply the Configuration.
If all goes well the Configuration will complete successfully. But you are not done.

7. First open a command window and navigate to c:\Program Files\Common Files\Enterprise Single Sign-On. Then use
ssoconfig –restoreSecret backupfilename
It will prompt you for the password showing you the password hint. This is why point 6 was so important if you don't have a backup or you don't know the password you are stuffed.

8.Open BizTalk Administration go to the Host Instances and add the ones that were originally there (which is why we did point 2 above). Use the same accounts and passwords and start them up.

9. Edit the BTSNTSvc.exe.config file and add any custom entries that you saved from point 5. Stop and restart the BizTalk Service(s).

That should be it, you should be up and running again. Its a pity Microsoft don't offer a better upgrade path than this.  If the full version is available on MSDN my advice is avoid using the evaluation copy.