Once you get the purchase email with the SuperCabinet IR Library license serial number, run TH-U and click LICENSES on the top menu to access the Manage Licenses window.
Here you just need to copy/paste the SuperCabinet IR Library serial number to the AUTHORIZE NEW PRODUCT box and click AUTHORIZE. The SuperCabinet IR Library will be authorized.
You will be prompted to select where to store the authorization.
Once you clicked the destination, the SuperCabinet IR Library will be ready to use.