You insert them into your vagina and then walk around (some people go about their day as usual and do groceries and such while others feel more comfortable staying in their house). If you feel the balls slipping, you tighten your kegels to keep it in.
It's exactly like practicing kegels by stopping a pee stream except that's actually bad for you whereas this isn't. It ensures you're flexing the right muscles and if you get heavier balls, adds resistance.
i heard a crap ton of stories on how to use ben wa balls and eggs, but i honestly still dont get it
It would probably be easier to get them and then try. Thats my plan. I really don't get it at all. I've tried numerous times to stop my pee stream. It just doesn't work. I'm pretty sure I do a good job working my muscles during sex, but then again I don't understand why that wouldn't translate to being able to use ben wa balls.