My "friend" used the drill method, and with some care and time you can get the steel wool bands and scrape all the crap off the insides of the cat with a decent enough sized hole. While you are in there, you might want to open up the ports, as there is lots of extra weld goop from where the flange attaches to the primaries. This is not a concern on the rear manifold, as it was made by a differnt vendor IIRC and the welds were done on the outside. My "friend" sealed the hole up by having it welded shut.
I recommend, I mean my "friend"
recommends taking the manifold off the car in order to do the job right. The rear CAN be done without removal, just take your time and wear adaquate eye and breath protection!
Cheap mod with good power gains...
