Have you ever had a coworker leave (voluntarily or otherwise) without checking in their changes in TFS? Annoying, right?
Unless you want those to be checked out (and possibly locked) forever, you’ll have to undo their checkout. Here’s the command:
tf undo /workspace:WORKSPACENAME;DOMAIN\username "$/path-to-file.txt" /s:http://tfs-server:8084/tfs