In this screencast we go through the process of installing a MODx Revolution install to the latest version. This particular upgrade was from 2.0.7-pl to 2.1.0-pl but the instructions should be pretty much the same for any versions of Revolution. I mention some important things to keep in mind before upgrading and give you a list of steps that I follow when doing my upgrades. I have also added this list below the screencast for your reference. We run into a couple of issues during this live upgrade and do a little troubleshooting.
These are the steps I ordinarily follow when doing my site upgrades as I mentioned in the screencast. If you can think of anything I've overlooked please feel free to post in the forums.
0. Review the notes about the new release
1. Clear your site cache
2. Disable FURLs
3. BACK UP your database and site files to a secure location
3a. Test the backup
4. Log out of the manager
5. Upload new files to your server
6. Run the installer in Upgrade mode
7. Log back in and check that everything works, enable FURLs
IF ANY PROBLEMS
Attempt to troubleshoot any problems, ask on the modxcms.com/forums.
Restore your backup if necessary