1. The Mars lens has a 'bump' to locate it correctly in the frame. This makes the lenses left/right specific. If the Moon lens does not have this bump then the answer would be no. 2. The C clip may break. I have had one shatter into 3 and fly off round the room, but others have just bent open and can be reused.
I found this elsewhere - works pretty good. Have only swapped once - no issues.
"Easiest way to take them off without breaking them or f'ing up your frame is to squeeze the orbital a bit to relieve the tension on the ring, rotate it until the gap lines up with the split in the frame, and gently, VERY GENTLY pry it apart with a small flat screwdriver tip that is not textured or rough (the clear handled Craftsman are usually polished or chromed, but the red/blue striped have ridges)...You may need to heat them a bit so they don't snap, but I have done them many times that way. When you put them back on, do the reverse and use the inside jaws of most needle nose pliers as they have a flat and smooth surface so they won't mark the glasses or rings."
there is a superficial one - by Walleva - piece of crap IMHO, doesn't really show the nitty gritty part with the clips - just removing and installing the lenses. Hope I am not violating any rules by posting a link to it here:
A better vid that provides a caution is by Thombs - nice overview of the Mars the good and the bad. But no actual handling of the clips, unfortunately, which is the really messy part.
I use the screwdriver in the slot method to open the c clip. I start with an ultra fine high quality flat screwdriver to start the process (so that I do not mark the frame coating by trying to force in a large blade), then switch to a heavier screwdriver to complete the task.
This does take a bit of force to do, so make sure you are working on a padded clean service to prevent damage to both the frame and the lense. There is also scope for sticking the screwdriver in your finger if it slips.
The after market c clips from Line Gear are not the same quality as the originals, but they do the job, and are easier to work with.
I am thinking about doing my own video of this Mars clip thingy. Maybe get my wife to video it - start to finish. No promises but perhaps a nice way to pay it forward. Maybe an iterative approach - get some comments and then adjust the vid until there is a good consensus of a few different tools and recommended approaches.
Thanks again qtrain23 for the lens cutting info. Now I can see I have some options for custom cutting some lenses for my Mars.
Any recommendations or maybe I should try it myself. I have have a Dremel tool. The lenses are a bit pricey to "practice" on though. Lots of folks point to Dr Chop and X-man. Perhaps I will check some local optometry shop see if they can recommend something.