SVN: Error 423 Locked

1. Ensure the file is not locked by someone else. (Right
Click-->TortoiseSVN-->Check for modifications [press check repo and
scroll right to see lock column])

a. If the file is listed here you can right click and
select 'Break Lock' then it should delete fine.

2. Perform a 'Get Lock' and make sure you check the box 'Steal
Locks'
3. Once you acquire the lock, then choose 'Release Lock'

(http://svn.haxx.se/tsvnusers/archive-2007-01/0127.shtml
http://stage.help.collab.net/index.jsp?topic=/faq/423locked.html)