How do you get a class C license?

I have had my class D for a year now. I'm 17 but turning 18 this summer. I was just wondering how do I upgrade to a class C because I'm sick on not being able to be on the roads after midnight!

How do you get a class C license?
Go to your states department of motor vehicles website.
Reply:I'm from Oklahoma and a class C license is for driving commercial vehicles, like box trucks. I have always had a class D license and have never had to be off the roads before midnight, what state do you live in because it must be different
Reply:whats class D?, im only 16 and already have a class C. Maybe its because i live in california
Reply:the only place that can revise the status of a drivers license is the Dept. of Motor Vehicles for your area
Reply:when you become 18 most states automatically upgrade you,and mail out a different license,or you get notified by mail,some states,wont do it ,if you have had a lot of tickets,or accidents,some states even make you wait till your 21,depends on the state,and the local guidelines they go by.