Instruction to installing Visio or Projects after the license has been assigned to them. 
Including instruction on how to confirm the license was assigned to them

The red arrows show where you can confirm if the license was assigned to them. They will have a checkmark in either box. 

To get the installer. Click on the waffle icon(9 dots in a square), Click on the "More apps" button. 

Click on the "Install apps", then click "Microsoft 365 apps"

If the users license was appropriately assigned. There will be a "Install Visio and/or Projects" button. Click on the button. A download will appear. Run the installed and the application will be installed. They can find it in the application ribbon on the start menu.