Hi Trish,
Congratulations on your pregnancy. If you haven't already had your baby - relax. You don't "need" to get birth breathing "right" to have a great birth. It's much better to not worry about it and let your body guide you on the day. You can wee, poo and vomit when you need to, and you can expel your baby when you need to also, so long as you are chilled. The only "rule" we would say is try not to hold your breath during this phase.
But for the fun of it, the idea is to breathe down slowly - as though breathing down through your vagina (though, of course, the air is actually going out of your nose or mouth). It's very similar to the outbreath of slow/surge breathing. You can put a little force behind it (with a slight grunt or "moo"), or do it nice and gently like in the first two videos - you can't plan this, your body will tell you, but do not hold your breath.
Practice each time you have a bowel movement, and you will start to "get" how it works.
Have a wonderful birth - and next time, book a practitioner so they can show you, guide you, and reassure you
