IT pushes out several pieces of optional software to a sort of "app store" type portal, which you can find by searching for "Company Portal" in the Start Menu.
Then you can either search or click on Apps in the left to find the software you are looking for. Once selected you will have the option to Install (or, if already installed you might see the option to Uninstall or Reinstall).
It can take several minutes depending on the size of the software to install, please leave Company Portal open while it installs.