With the spring season approaching, it will soon be time to change my tires. I have a set of 17" winter rims which I got with my snow tires. I have never changed the tires in my G before - should I take it in to a tire shop? Or is this something I can do myself....

I don't have a torque wrench, but I was talking to a friend in Calgary here who changes his tires every year without a proper torque wrench. Could this cause a problem?

How does the TPMS work? Is there some kind of wire in the rims that needs to be hooked up?

I kind of figure that if I got a flat, I'd just be changing off the tires without a torque wrench to begin with - are they actually needed?