how to update 2019a version??

Now i am using matlab 2018b version in ubuntu.

I want to upgrade my version to 2019a, but i don't know how to upgrade.

I install 2019a but it installed individually with 2018b version.

thank you for your answer previously.

[Walter Roberson]

There is no upgrade. Each version can be installed with the rest still there. When you no longer need the old one you uninstall it.