How do people learn to play unusual instruments (like a church organ or a carillon)?

This was on Wikipedia’s front page today:

In July 2022 the organ was installed at London Bridge station − in the Stainer Street concourse, near Saint Thomas Street − by the “Pipe Up for Pipe Organs” charity project led by the organ restorer Martin Renshaw. Its relocation helped to save the organ and raise public awareness of the loss of pipe organs from closed churches.[1][4][5] It is freely available for anyone to play,[6] and the Future for Religious Heritage organisation believes it to be the “world’s first open-access railway station pipe organ”.[6]

I’m just going to drop this here:

Oh gosh that puts a smile on one’s face. Glorious.