From my experience, you can just backup - rename - and restore again (in case you reinstall the server). In case you don't wan't to reinstall the server - just rename, then you need to disconnect from server configuration - rename - connect. Don't forget to keep all custom assemblies, files and web.config with you.
You have to be carefull, when you disconnect the server from server farm - SharePoint will delete all IIS - folder, and configuration. So make a physicall backup for any assemblies - and custom files you might have.
Regards,
Riwut Libinuko
-http://cakriwut.wordpress.com-
*please rate me, if this was helpful
Best regards,
Riwut Libinuko
SharePoint Architect, Singapore
Microsoft MVP | SharePoint Server | Singapore | cakriwut@gmail.com
**Please let me know if you need more information**