With the CMS installed and when in the admin, you will see a button on the navigation that will show if an upgrade is available. Along with upgrading through the CMS, you have one other option when proceeding.
If you pulled down the repository manually, you can simply run a
git pull which will update the necessary files in the new version of the CMS.
Otherwise, if you did a
composer require to pull in the CMS, continue on after clicking on upgrade to proceed with the update. If anything failed, there should be a rollback that occurs. Otherwise, you may need to manually look at any files that changed. We highly recommend setting up the CMS in a git repo under your control, especially since running
git status can quickly help you find any issues that popped up.
After the upgrade is complete, run
yarn run prod to ensure the latest UI has been built for the admin and public side.