Like other's have said popping or using a proper diameter prop kit for your snakes age is the only way to find out the sex a snake. Popping definately takes a bit of time to get your hand's right and to have the bp relaxed. I learned how to pop my two normal's from a video from J kobylka (he show's how to properly pop and how to properly use a prop kit).
If, your not confident in trying to sex them yourself? Then I would definately not suggest you try. Have a experienced breeder do so or have your herp vet do it.
