Paul's kind of on the right track, though really my answer might surprise you...
DON'T! Do not even bother 'slicing' it. This is part of why the PSD first approach is, well... flawed. I'd end up making an all new image to handle that.
First, to keep the filesize down, the 100% width uniform green bar? Use bottom-border to make that. Likewise, the "call us" text? GET THAT AS TEXT ON THE PAGE!
Though the real magic? That center 662x204 area is going to be 10-12k no matter how well you encode it unless you resort to going nuts with jpeg; Me, I'd use .png, but get this; I'd make it a single image with the entire background on it as 3072x224. PNG encoding will make that a single 12K file. Saves you two handshakes, which should balance out the half a k that extra long repeated area ends up.
Finally, I'd toss it ALL into a H1, no separate div needed, with a bunch of nested span, and a empty bold tag for the image replacement.
Which 'working' looks something like this:
<span>Table & Chair Inc
<span>CALL US: (519) 585 1000</span>
Be sure to look at it with images disabled to see what I was doing with all those extra span...
Though with that specific image, I'd consider taking it a step further, and removing almost ALL of the image elements. As it is you've got some rather ugly aliasing going on on those border lines -- while HTML borders would be nice and crisp.
Gimme a bit, I needed a challenge, let's see just how much of that 'image' we can just get rid of.