Also, how do you keep your pants clean when you pull them down?
It's a bit complicated...roll up your pants a few inches so they don't touch the floor when you lower them. When you pull them down to your knees, and squat, your pants are in front of you because your tush is behind you in a squat. You can't get your pants dirty doing what you have to do, but they can get dirty on the floor, so I recommend rolling up the legs. Long skirt? Gather it up and toss it over a shoulder...
Or, just look for a stall with a western toilet mark! Much easier! Westerners tend in general to be a bit less flexible...the Japanese sit on their legs on the floor and so they are pretty bendy
. Their heels are on the ground when they squat, they can squat and just sit there. For westerners who grew up using chairs, there's less flexibility (I think in the hamstrings) so an unsupported squat is difficult. A lot of people hold onto the pipe connecting the squat toilet to the water tank , but sometimes the pipes break off if they're old...lots of stories on ex-pat websites about squat toilet contortions
They are being phased out here, or at least both are offered, because of the great number of older Japanese getting knee and hip replacements. A total knee makes using one impossible.