Actually, neither are necessary. I needed to remove only the lower shock bolt and swing it away. Didn't need to touch the exhaust at all. Once I removed the cotter pin, being careful to not scratch the chrome (which was covered with a towel) and loosened the nut I began to push the axle, with nut still attached, out, which gave me more room to work the nut (using a 27mm open end wrench). Once everything was loose I was able to finagle the swingarm away from the frame just enough to slip the belt in. All in all the job was a bit easier than I expected, but still quite involved.