Cumulus 1.9.3 (build 1059) is now available from the downloads page.

To upgrade from a previous version, just run the installer and install to the same place as your existing installation (the installer should offer this as the default). If you don't want the installer to overwrite your web templates (because you have modified yours, for example), you can deselect the option to install them during the installation. The new templates will still be installed to web\originals so that you can look at them.

Cumulus Download Page