Learn English – Meaning of “I’ll break it for him,” (Chapter 3 Moby Dick)

I'm Indonesian, and currently reading Moby Dick. In chapter 3 I found a phrase that I can't get to know its meaning. The sentence is:

"Landlord!" said I, "what sort of a chap is he – does he always keep such late hours?" It was now hard upon twelve o'clock.

The landlord chuckled again with his lean chuckle, and seemed to be mightily tickled at something beyond my comprehension. "No," he answered, "generally he's an early bird—airley to bed and airley to rise—yes, he's the bird what catches the worm. But to-night he went out a peddling, you see, and I don't see what on airth keeps him so late, unless, may be, he can't sell his head."

"Can't sell his head?—What sort of a bamboozingly story is this you are telling me?" getting into a towering rage. "Do you pretend to say, landlord, that this harpooneer is actually engaged this blessed Saturday night, or rather Sunday morning, in peddling his head around this town?"

"That's precisely it," said the landlord, "and I told him he couldn't sell it here, the market's overstocked."

"With what?" shouted I.

"With heads to be sure; ain't there too many heads in the world?"

"I tell you what it is, landlord," said I quite calmly, "you'd better stop spinning that yarn to me—I'm not green."

"May be not," taking out a stick and whittling a toothpick, "but I rayther guess you'll be done brown if that ere harpooneer hears you a slanderin' his head."

"I'll break it for him," said I, now flying into a passion again at this unaccountable farrago of the landlord's.

"It's broke a'ready," said he.

"Broke," said I — "Broke, do you mean?"

"Sartain, and that's the very reason he can't sell it, I guess." _{Moby Dick}

What does it mean? Is it 'fleeing' or 'stopping'?

Best Regards.