One thing I like about dealing with privately owned shops, they can do what they want...my tire shop cut the cladding for me no problem, no hesitation. I can imagine the chain stores might decline to do it.
Here's a real nice "tire calculator" with great visualization of the difference between 2 tires sizes, it also provides all the calculations (width, tall, circumference etc)....plus it gives the speedometer differential so you'll know exactly what your real speed it. Mine came out to be 10%...nice and easy to calculate.
http://www.rimsntires.com/rt_specs.jsp
And yes, Rick's link to the key fob programming instructions are correct, same as the one I listed above.