If you used Subversion to install Elgg using SSH, upgrading to Elgg 1.1 stable is a snap. Simply log in and:
svn sw https://code.elgg.org/elgg/releases/core/elgg1.1/ .
Make sure you include the space and period. Press enter, then agree to accept the security certificate typing t for temporarily or p for permanently. The files will scroll quickly as they are transferred from server to server.
When the transfer is done, open your browser and go to yourelggdirectory.upgrade.php
You should get a message saying the database has been upgraded and land on the login page. Log in and check your version. It should say 1.1 Stable.
Always have a backup of both the files and the database in case something goes wrong. I have done this svn upgrade with the original 1.0 release, and the 1.1 RC1 from the trunk. Note that older themes may exhibit minor quirks.
That’s it. It only takes a minute or two.