SVN Commit Log Message Correction
Have you ever done a commit and then realized that the message you put wasn’t quite right? It is possible to change those messages using the Subversion admin tools.
From the Subversion book: Commit Log Message Correction
Example:
[admin@svn]$ echo "Here is the new, correct log message" > newlog.txt
[admin@svn]$ svnadmin setlog myrepos newlog.txt -r 388 --bypass-hooks