If, like me, you own a Leica with the little red dot, and would like to change it to black to remain more unnoticeable, you can try this:
- Remove the red dot. It is held by an adhesive that should be fairly soft and supple, making it easy to remove.
- Use a Dremel tool with a finishing abrasive buff attachment to remove the paint. The underlying material should be some sort of metal, so it ought to survive the process fairly well. Do not use coarse sandpaper as it will wear down the raised metal parts.
- Because I did not want to put white paint on the lettering, preferring to let the metal show, all I did next was to spray the whole dot with black enamel paint. I put on two coats and waited for two days before proceeding. It is essential to let the enamel dry completely. Otherwise you will end up with a big goopy mess and will just have to strip and repaint.
- Use a super fine wet-sanding paper to gently sand off the paint from the raised lettering. You may also like to sand around the lettering if the enamel finish was not perfect. The key is to fold the sandpaper in such a way that only the lettering is exposed to the abrasion. It takes a while but you will get there.