Plan the Upgrade
You should read the Release Notes for the version you are upgrading to in order to understand the new features in the version, and to identify any special activity that might be needed in order to do the upgrade.
It is best practice to install the upgrade and to use it on small projects before moving it into production.
This installation guide describes placing the upgrade files into a separate location from the current release to support the ability to have both the current version and the upgrade version available at the same time.