How do you get high off of Mucinex DM?

I've done lots of research on this drug, and from what i hear, one of the two active ingredients (Dextromethorphan) can make you high. But the other active ingredient, (Gauifenesin) can cause aggresive vommiting and that you shouldnt take more than 2,400 mg. The pills are 3/4 green and 1/4 white. Is the green part Gauifenesin? If so, i can split them. If not, how many would i have to take to get high? I've used Mucinex DM before. But never to get high.