Part numbers for the Surface Studio "1" fans?

I have a noisy fan in my old Surface Studio “1”. I am concerned that the noisy fan will turn into a slow fan, and then a broken fan, and then my system will overheat constantly, making the user experience sub-par.

Somebody said “the fans are really easy to replace”, and even posted a price, but nobody has described just what the fans are and where to obtain them.

Thanks!