Well look here is the best way as I did it ok the H2 has to Cats ,,,so one at a time take of the front pipe that hold the cats now this bit is important the bulge area where the cats are make sure you cut into the cat from the top i.e. open it up cut in so you can wedged open like a flap from the top of the cat take out the brick filter ,,,push back the flap weld it up put some little paste round the weld ,,their you are the cats look like there still there ,,no one can see that you have de cated them as you cut in from above easy