It's not much of a 'how-to' - but I wanted to go back to the original black mirrors which the "S" model of the Liberty came with.
(I bought a chrome pair back when the price was less than $20 ea.)
The Piaggio flyscreen is in the way - but it can be lifted off by loosening the 4 set screws on the front.
Then the mirrors can be spun off past the support bars.
Use a 17MM wrench to snug in place.