How to undo pending changes by others

TFS source control differs significantly form VSS. e.g. when I want to undo pending changes by others, where should I start? - no UI command menu, only command-line utility available, the tf.exe

The document in msdn is not clear enough (maybe only to myself ):

tf undo [/workspace:workspacename[;workspaceowner]] 
[/server:servername] [/recursive] itemspec [/noprompt

http://msdn2.microsoft.com/en-us/library/c72skhw4(VS.80).aspx
Two notes for above command:
1. workspaceowner - don't forget domain name if a domain user e.g. MyDomain/AnotherUserName
2. itemspec - try to use the fullpath if no luck e.g. $/ProjectName/trunk/FolderName/FileName.cs