Today I replaced the original rear tire with the same size Michelin Pilot Activ. The original tire had 8,000 miles on it. It had not yet reached the wear bars, but had flattened out quite a bit and the new tire should improve cornering and steering accuracy, as well as provide better dry and wet weather traction.
I have removed and reinstalled a lot of motorcycle rear wheels over the past 50 years and the Zero was the easiest that I have ever worked on. The axle came out easily, and the wheel dropped out without hitting anything, once the rear caliper was removed by pulling the two fasteners. When removing the axle don't forget to first loosen the pinch bolts located at the rear of the swing arm. All bolts use a 5mm Allen hex wrench (or bit) to loosen. The wheel also went back into the swing arm easier than any other bike that I have ever worked on. Everything fit easily and no force was needed to install the wheel and its spacers and to insert the axle.
The only real hassle was removing and reinstalling the tire. The rear wheel is a very nice casting and the paint is beautiful, but the wheel design has a very small drop rim and that makes it quite difficult to lever the old tire off and lever the new tire back on. I had to resort to using my large, dished, metal tire irons, which scratched the finish during the last struggle to get the new tire bead over the rim. I had warmed the tire and lubricated the bead with soapy water first, which greatly helps the installation. On the other hand, I didn't have to use my pressurized air tank to seat the tire on the rim. Just using a bicycle floor pump was sufficient to inflate the tire and seat the bead after pressurizing the tire to 45 pounds.
Anyone wanting to change their own tire should consider buying a Drag Specialties scissor lift. It worked perfectly to lift the bike under the belly pan and supported it securely while I removed and replaced the rear wheel. The wheel did need the stock wheel weights removed and new ones replaced at a different location. Three weights were removed and two weights were installed at a location near opposite of the old weights.
Due to the difficulty of replacing the tire on the wheel, I would recommend to anyone who is not experienced with this task to just remove the wheel and take it to a shop and let them perform this task. You will save a lot of effort and preserve the finish on your wheel, compared with performing the work using hand tools on a cardboard garage floor, especially if you are working by yourself.