This is funny. When I first read the question, I thought it a humorous prank. But, half way through the page, I was sort of convinced that it may possibly not have been intended to be.

I have used squat toilets for nearly all my life. At home, we have both the squat toilets and the sitting ones. I don't mind either, but I find the squat toilets to be more hygienic, especially when they are shared among people (especially in the case of public toilets), than the normal, sitting ones. You can probably take a guess why.

I'll be honest, I've never used a squat toilet with my trousers still hanging down my knees. I can't ever imagine doing that. In all our washrooms, we have ample hanging hooks. So every time I use it, I take off my trousers/boxers. It's much easier that way, and you don't have to worry about trying to keep your trouser/boxer from getting dirty or soaked. In other words, you can be at peace with yourself. :)

So you squat down with your behind facing the wider side of the toilet opening (don't attempt to sit the other way round, lest you want to risk making a mess, for obvious reasons). You can decide to squat down in whichever fashion you feel the most comfortable and keep your arms bent a little and pressed against the length of your thighs. Yes, after a period of time, your legs will start to get tired and then numb. That's just one of the things you'll have to get used to or learn to deal with.

The water pot, or what is popularly known in the Subcontinent as "lota", is what you fill water with. I hold it with my right hand, pour the water down, and wipe off with my left. That's only if you wash with water. If not, you can use the tissue roll which is supposedly fixed into a roll holder at an arm's reach from the toilet. If a toilet doesn't have it and you are only used to using a tissue roll, you ought to get one yourself before embarking on this mission. As someone pointed out already, be sure to run the flush of the toilet after you've finished and got up from squatting down. In all our washrooms, we also have washstand nearby, so when we are done working on the toilet, we get up and wash our hands, and then put on our trousers/boxers/whatever, and also flush the toilet. A word of advice though: If you don't have a tissue roll and are planning on washing with water in a public toilet or a toilet not at home, be sure to fill the water pot first before doing anything. I know it sounds silly, but it has happened to people I know in a lot of public washrooms. In some places, the water supply does run out, maybe because the tank providing the water got empty and the owner or person in charge forgot to run the water motor to fill it up that morning.

And that's pretty much it. It's not really rocket science -- well, maybe.