Unlocking an item in Team System
I've tried unlocking another person's file three times from the docs (here) and have failed. Most blog entries just repeat the doc signature. However, this blog entry has the magic potion. Inspect this sample command line closely and hope the TSF team fixes the GUI in Orcas.
tf undo "$/MyProject/VersionX/Utils/file.cs" /WORKSPACE:MaorDev;Domain\User /server:MyServerName /recursive
Also useful is the tf workspaces command to find workspace, user, and server info. Good luck!