there isn't a myth 3 but there is a myth g2 regulator. Its easily recognised by a gold coloured thread like the one
HERE.
If it is you can see from the image that to rotate it, you must unscrew and remove the top flange by inserting the correct size allen key in the top and depressing the pin. Make sure your tank is completely empty of air or you won't be able to do this very easily. once you remove the top flange you'll see that when you lift the gold thread off, there are 4 studs that fit in to place on the regulator body. rotate the thread as required and seat it properly back in the holes. replace the top flange using the allen key and that is you good to go.
edit: i'm saying 4 studs but not sure that's correct; either way turn it until it sits firmly in place.