There are two ways you can upgrade a tablet to the latest Ocean Tablet app:
If you are upgrading only one or two tablets:
If you're only upgrading one or two tablets and the tablets are in front of you, tap the cog in the bottom left hand corner. Enter your Ocean user credentials and choose "Update Ocean Tablet". The upgrade should only take a minute but you'll need to repeat it for all the tablets you want to upgrade.
If you are upgrading many tablets at once:
If you're upgrading many tablets, it may be easier to use the Ocean web portal to trigger the tablets to upgrade. Log in to the Ocean portal on your computer's web browser, go to the Tablets tab and find the tablet(s) you want to upgrade. You can click them and an option to upgrade them will appear. The next time those tablets are used, they will upgrade themselves.
Please refer to this article for more information on how often to upgrade your tablets.