Glass Scratched over camera

My Red Hydrogen One has a scratch on the glass cover over one of the back camera lenses. This appears in pictures.
Any ideas on how to get the glass replaced?
If I can get a new piece made, can I replace it myself?

I have read in the h4v forum that someone had it fixed by a watchmaker. I don’t know how easy it could be to remove the glass.
Having tried a clock film to protect the glass, in that case I can assume that the main drawback will be that it is no longer possible to use flash (not a big issue). Some possibility of extra glare in some conditions