I've recently learnt to pop snakes. I think you're not going to get it from watching videos or reading alone. It could be quite dangerous too if you don't do it right so for the first time I think you should have someone experienced there.
Also, if you manage to pop out any hemipenes, then you know its a male but if nothing comes out, you can't really be sure that it is female or that you just didn't do it right until you are more experiened.