Those crazy boys of summer are back. We're talking, of course, about Bradley Cooper, Zach Galifianakis and Ed Helms, stars of the highly anticipated "Hangover Part II." At the film's NYC premiere earlier this week, the guys told us about the "chaos" of their pre-release press blitz, and now, MTV News takes you inside the chaos of filming the "Hangover" sequel.

When talking about how the photo montages at the ends of both films were compiled, Cooper and Galifianakis ended up in a back-and-forth about Cooper's head-shaving skills.

"It runs a similar course as the filming of the movie," Cooper said when asked about when the photos for the montages were taken. "We would allocate time in the shooting day to do stills throughout the movie, so at the end, you have all the stills, but it's not like we have two days and we shoot all the stills; it's throughout the whole film."

With regard to Galifianakis' shaved head, which occurs during a scene in the film, we wanted to know if the actual clipping was performed by Cooper.

"Yeah," Cooper said. "I did a nice job."

"I mean, it's pretty easy," Galifianakis pointed out.

"It's not that easy," Cooper protested. "Your ears are very tight to your face."

"Bradley, everybody has a template. I mean, look at that picture," Galifianakis said, pointing to the film's promo poster, which features a photo of Galifianakis with a perfectly buzzed coif. "What I'm saying is, it's so easy to shave someone's head."

"I'm telling you, I did such a good job shaving his head they had to mess it up more, right? Tell them," Cooper insisted. "Tell them, Zach."

"Yes. That's true," Galifianakis said, relenting. "He did such a great job they had to mess up my hair more."

"Thank you," Cooper said, sounding pleased to receive the recognition.

Check out everything we've got on "The Hangover Part II."

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