To update from a previous SmartSVN version (>= 4), do the following steps:

1) Move the old SmartSVN version to the trash.
   Note: If you have installed the SmartSVN Finder integration, you can't
         empty the trash now because the Finder still has locked the Finder
         integration plug-in.

2) Unpack the new SmartSVN version to the original location.

3) Restart the Finder. This can be done, for example, by holding down the
   Option ("alt") and Control ("ctrl") keys while clicking the Finder icon in
   the Dock and selecting 'Relaunch'. Alternatively you simply can log out and
   in again.

4) Now you should be able to empty the trash containing the old SmartSVN
   version.
