2
1. Download the
upgrade packages for each version of XOOPS.
2. Backup your site's file structure, database and templates before you start, so that if something goes wrong you can restore your site to its original state.
3. Progressively apply the upgrade packages one at a time and check that everything is working before you move on to the next one.
Please make sure that you read the upgrade instructions / readme for each package. The normal procedure is to overwrite the files on the server / update the system module, but sometimes there are additional steps. For example, some require you to run an upgrade script as well.
Check the readme files in each package, and good idea to check the corresponding xoops.org news stories about each release, as sometimes they contain additional information.