Stock cat-back bolt removal problem

I can not get the two bolts unscrewed off the cat/long pre muffler pipe. I tried spraying it with WD-40 and waitng and no luck. I tried putting a pipe on the end of the handle of the socket wrench for more torque and nothing. This sucks. I bought a magnaflow cat-back to install and can not do anything about it. My truck is only 8 months old and those bolts are all rusted to shit. Did the Michigan winter rust the underside of my truck that bad? Any helplful ideas would be appreciated.