How to uninstall the SQL Server 2008 SP 2?
This Feature is in introduced in SQL Server 2008 SP1
and above.
Before you do the activity, it is recommended to
take a full instance backup just in case to recover if anything goes wrong.
Check the Current Service pack level of the SQL
Server Instance.
Go to "Programs and Features" options in
Control Panel and click on "view installed updates"
Highlight the Service Pack you want to uninstall and
click "Uninstall"
The uninstall Service Pack for SQL Server wizard
will now come up and click "Next" here once the update rules have
been verified.
Select the features for which you need to remove
service pack and click "Next"
Once the file check is completed, Click
"Next"
Verify the Summary and click "Remove"
Wait for the process to complete
Once this is completed, Restart the computer to
finish the SQL Server Setup.
Now verify the changes