How do you become Machiavellian?

So, id like to become more of a machiavellian character. I've generally been the stereotype "nice guy", and to be honest, i haven't really had problems with that. It's always worked for me, but I'm just finding it really restrictive in social settings. Often ive found that my "niceness" usually arises more from a fear of upsetting people as opposed to genuine kindness. Like, caring too much about other people's image of me. So, I wanna know how to loosen up really. I guess confidence comes into it, but I want to be able to play games with people, be manipulative, and just generally well, not be a jerk, but have power over people? Very related to the dark triad. I know a lot of its genetic, but i want to develop it as much as possible. So yea, I know it sounds a bit wierd. But any tips or advice would be most welcome! Oh, and im an 18 year old guy if that matters