Evaluate the Klein-Gordon action

1. Apr 16, 2008

auditor

[SOLVED] Evaluate the Klein-Gordon action

I'm interested in evaluating the Klein-Gordon action in P&S, p. 287. It goes as follows
$$S_0 = \frac{1}{2} \int d^4 x \! \phi \left( - \partial^2 -m^2 \right) \phi + \left(\text{surface term} \right)$$
The surface terms drops out, that's fine. I would like to see a detailed calculation of the first part of the integral. Anyone to the rescue?