You still really shouldn't do it on your own, looking up how to do something on the internet and attempting vs watching/helping someone do it several times in person before attempting are way different. Don't try it, if you really must second guess the breeder on gender then get someone with experience to do it.
These snakes are living creatures and like any deserve more respect than to be idly experimented on; they can feel discomfort, they can feel pain, and they can be severely injured in many ways by improper probing. Just because youve had him for a little bit and have read up on a lot of info doesnt mean you're an expert and doesn't mean you have experience, you just got the animal, try getting the basics down and experience OWNING him for a little while before you even consider poking and prodding and sticking things in your snake. There really is no good reason to probe him other than you wanting to see if you can do it, and in my opinion thats a recipe for disaster and by FAR not worth the risk.