By being an adult who lives in his own place.
Oh, you want me to be sensible? Fine. When I was a child living at home, well, I hardly had any video games. My parents acted strict with games, but honestly as long as my school grades were good and I still did some other activities, they just let me play the few games I had.
I got bollocked for playing RuneScape until 2 in the morning many a time, but my grades and other activities were fine, so it there were never any consequences beyond being yelled at initially. I just got told it was my own fault for being sleepy and to move my arse.
So, do your school/home work, do other activities other than gaming, and your parents will probably let you play games.