When you create an override and don’t save it to a custom unsealed Management Pack it will save to the Microsoft.SystemCenter.OperationsManager.DefaultUser.xml management pack by default. You do not want it to write to the Default MP as this will come back to haunt you at some point when you want to remove the effected management pack. This is why you should always save any changes to your own custom unsealed management pack…..
But if you do happen to accidently write something back to the default MP, then here is how you can remove the dependencies. NOTE Before doing any of this please backup your management packs!
1. Download and install Microsoft’s XML Notepad
2. Export the Default management pack to any folder you like. This will export it into an XML file. Back this file up before making changes to it.
3. Open the XML file in XML Notepad
4. Expand the management pack in the left window to \\managmentPack\Manifest\References
5. Look in each sub-folder named Reference for the Management pack that you are trying to remove. Once you find it Delete the Reference folder.
6. Import the Default XML file back into the console.
7. Try to delete the management pack again.
These links are also worth looking at as they go into more detail on this…..