Cannot remove build agent from build controller because it is reserved for a build

After upgrading my TFS 2010 installation from Beta 2 to RTM I noticed that my build agent stopped working.  I also noticed that I was unable to delete the build agent with an error message along the lines of "Cannot remove build agent [agent name] from build controller because it is currently reserved for a build".

I'm pleased to announce that I finally figured out how to resolve the issue.

In SQL Server Management Studio connect to your team project collection db (tfs_[collection name].

Execute the following SQL statement:

SELECT * FROM tbl_BuildAgent

Locate the build agent in question then note the value of ReservationId and AgentId.

Execute the following SQL statements:

DELETE FROM tbl_BuildAgentReservation WHERE ReservationId = [ReservationId]

UPDATE tbl_BuildAgent SET ReservationId = NULL WHERE AgentId = [AgentId].

Once that was done I was able to successfully remove the Build Agent from TFS Admin Console.