Delete workspace on Team Foundation Server

How is it possible to delete a workspace on a machine who's main user account is locked ?
1. Get the whole list of workspaces :

C:\Program Files\Microsoft Visual Studio 8\Common7\IDE>tf workspaces 
/server:http://servername:serverport/ /owner:*

this gives a list like :

Workspace                          Owner      Computer   Comment
---------------------------------- ---------- ---------- ---------------------
CIS000274                          USER1      CIS000274
CIS000605                          USER2      CIS000605
CIS000957                          USER3      CIS000957
CIS001242                          GONEUSR    CIS001242
CIS001242                          USER4      CIS001242
CIS001317                          USER5      CIS001317
...

2. Find the one you want to delete.
3. To delete the workspace for user GONEUSR, I only need to do :

C:\Program Files\Microsoft Visual Studio 8\Common7\IDE>tf workspace /delete 
CIS001242;DOMAIN\GONEUSR /server:http://servername:serverport/

A deleted workspace cannot be recovered.
Workspace 'CIS001242;DOMAIN\GONEUSR' on server 'http://servername:serverport/' has
151 pending change(s).
Are you sure you want to delete the workspace? (Yes/No) y

And it's done.