i just did mine and a friends a few months ago and its not hard at all. like swazo said, cut that 1/2" hole and what i did was i got piece of thick welding rod and bent it and just knocked it around for about an hour to get it all out. i dont know about welding a patch onto that surface but i just got a short bolt that fit the hole, tapped it and locktite and that beatch hasnt moved. oh and make sure to enjoy the sound your sh*t makes when the pipes are off
