There are lots of threads about this, search the performance threads about this... On a V6 you take them both off the car. The rear one is simple, you just unbolt it from the rest of the exhaust then stick a screwdriver up it and clear it out. The front one, you cut a window on the bottom of the manifold so you can get to the cat material, then weld the window back up. If you have a V6, make sure you fix both of them. -Nick
