Be Careful
Those are fantastic instructions above... Remember to find a FLAT part of the manifold, or you'll spend forever and a day trying to start the brass fitting into the new threads (I learned the hard way).
Everybody's got an opinion on whether to pull the turbo or not... I pulled it, and when I did, found a bad gasket on the oil drain tube that I wouldn't have found any other way. It comes off in about 15 minutes if you decide to go that way, and you won't have to worry about what shavings a magnet might miss. You can also 'feel' the threads and brass fitting from the inside to make it as smooth as possible.
Good luck!