Once an mpp is associated with a team project how is it unassociated with a team project?

Not sure I understand your question. Why do you want to unassociate an mpp from the team project? Are you asking how you can disconnect the mpp from a TFS server and project?

Thanks!

Yes that is what I mean. I want to disconnect the Project file from a TFS Server and a Team Project. It does not need to be associated with the given Team Server or Team Project.

There isn't an easy way to do this from the UI. The workaround is listed below:

1. Close Project
2. Right click on the mpp file and choose Properties.
3. Choose the Custom tab in the Properties window.
4. Choose any Property listed there named "VS Team System Data Do Not Edit" and click Remove.
5. Click Apply or Ok.
6. Open the mpp file and you will get a message saying its not associated with any TFS server. Click Ok and Save it
7. You will not get the error message everytime you open the mpp file as long as you save it once after the message is received.

Let me know if this works.

If you have an MS Project Server project instead of an mpp file, you can unbind it from TFS Team project following this steps:

1. Close MS Project.
2. Disable the TFS addin by going to HKLM\Software\Microsoft\Office\MS Project\Addins\TfcOfficeShim.Connect and change the ??oadBehavior??from ????to ????
3. Open your project from Project server
4. Choose Properties from the File menu
5. Choose the Custom tab in the Properties window.
6. Choose any Property listed there named "VS Team System Data Do Not Edit" and click Remove.
7. Click Apply or Ok.
8. Close MS Project
9. Re-enable the TFS addin by going to HKLM\Software\Microsoft\Office\MS Project\Addins\TfcOfficeShim.Connect and change the ??oadBehavior??from ????to ????
10. Re-open your project from Project server and it is now unassociated from TFS