You do not need to take out the tires, but some people do. It should only take 5-10 min. but get a friend to help you hold the cans as you slip it out. They could get heavy. I think they weigh more than 25lbs. each!!

 

much easier with some ramps. it would probably easier to remove the muffler with the wheels off, but why go through the hassle of jacking the car up and removing the wheels?
just roll it up on the ramps and you could take out the mufflers in 1-2 hours, depending on how thin your arms are and how you fit under the car.

 

You need to jack up the car or it'll be a PIA, wheels can stay on and bumper. They slip right out but you need a friend as yes about 25lbs each. You probably need a set of new tail pipes clamps as both of mine broke while taking them off, they're only $14/each at the dealer but worth having them handy.