If you have a short torso, I can definitely see that being a problem. The belt will get more pliable over time, but I doubt it will become supple enough to not dig into your hips/ribcage. You can either do as Reed said, and wear it higher, or suck it up and deal with it for a while. Mine dug into my sides at first, but I don't notice it anymore - much as it doesn't hurt to have the bare bar on my back like it did when I was younger. I also recommend having as little material under/around the belt as possible. Unless you always wear a singlet, your shirt and shorts probably bunch up in the belt. Pull your shorts down below the belt and smooth your shirt out as much as possible under the belt.
As for breaking it in, wear it all the time. Sweat into it a lot. Some dudes recommend putting it in the washing machine, or rubbing it with mineral oil, or parking your car on it. Mine broke in just fine after a few weeks of constant use. Mine is made of sole leather though; wouldn't run a suede belt through the washing machine or put oil on it.