Although I have stopped using since 16, I can still remembered how difficult it was to get use to one. It was just unnatural. You will need to followings,
An ability to hold your breath
Hand sanitizer gel
This is a hole in the ground that may or may not include a flushing system. You have to practice famous martial art like taiji to master the technique. Just hilarious!
(Link)Wiki HowTo, How to Use a Squat Toilet.