Using BalenaEtcher, write the file to the micro SD Card. This may take 5-10 minutes. Wake your computer if it "sleeps."
Open up the back of the clock.
Remove the current SD card from the Raspberry Pi. It will have a green dot on it. For safekeeping put it in the plastic case that the extra SD card came in.
See the image below and video here if needed, the SD card is on the bottom of the green board.
Insert the new SD card, with the update, into the Raspberry Pi, where you removed the old one from.
Turn the power on, there's an on-off switch on the right. Small lights should turn on Raspberry pi if it is powered and a few seconds later it will turn on.
Check that the display now shows the update.
The arrow is pointing to the Raspberry pi in the picture below: