He put the part into a big vice, went at it with his torch, stood on the table, and with all of his weight bore down on the old joint with the pneumatic hammer. First he went arount the outside perimeter of the joint itself, then hammered away at the middle. Be careful of stuff popping out when you torch it...there may be hot grease and metal parts flying outta there. (wear safety glasses)
Putting the new ones in was relatively uneventful, although a big vice, and that tool, is definately a big help
Good Luck!
-Larry