To manually remove all Visual Policy Manager (VPM) rules and policies that apply to the realm you want to remove:
Note: When following 1.b for removing affected rules and policies, you must respect the format of the XML file. If you do not respect the format then when re-importing the backup and opening the VPM it will not open up with the policies. In notepad++, for example, is how to save correctly the policy files. Set the encoding as xml extension
Once completed you can now open the XML document with the normal notepad and now it respects the format of the XML
Back up your policy files:
Log into the Management Console and select Configuration > Policy > Policy Files.
Save the Local, Forward, and Central policy files by copying and pasting their content from Text Editor to a text editor, such as Notepad.
Remove the content from the Local, Forward, and Central policy files.