Is it easy to take off the tires. what tools? how long does it take.
Not too time consuming. First you would have to remove the exhaust. The brake caliper has to be removed from the swing arm, rear shock and the back wheel mud guard. (no need to remove the hydraulic lines on brake caliper) and then the swing arm itself. You would need a socket set of various sizes.
The wheel nut will have to come off with a 24mm socket. (it's quite a big sized nut).
Once you remove the wheel, the tire is a pain in the butt. I recommend you to take the entire wheel to the garage and have them install the new tire with a hydraulic press.
I changed my tire yesterday and it's all still fresh in my head.
Best of luck.
Cheers