This is by far the easiest thing to do if you use the installer, simply have you MS Backup not modded, and run “Uninstall Softmod” and all will be done automatically, just make sure you read the onscreen options so you don’t run into any mistakes when it comes to deleting all other files on E:\.
The Uninstall feature will do it all for you, but you’ll get prompt for special actions, on prompts, you don’t have to say “YES” unless it’s what you want to do.