You can update a package while in the In Project, Unity Registry, or My Registries context:
Open the Package Manager window and select In Project from the Packages drop-down menu.
An arrow indicator appears next to any packages that have updates available.
In the list of packages, click the expander icon to the left of the package name.
If there are updates available, the latest version and verified version appear along with the See all versions link.
Click See all versions to see the list of all available versions for that package.
You can select any of these versions for the current package and see the details specific to that version in the details view.
Click the Update to button.
When the progress bar finishes, the new package version information appears in the details view, and any new functionality is immediately available.
Note: If you switch to an older version of a package, you might have to run the API Updater on the package contents.