In full disclosure, I'm not a mechanic and nowhere near the experience/knowledge others have here on this forum. But I see no one has replied yet to this post.
I've done two ignition switches on my 2000, the last one was just this Sunday. I know of no special trick to disconnect the harness. Both of mine have been a SOB to disconnect. The 7 mm bolt is really the only thing that connects the harness. Once you have it loosened you need to man handle it. I had to lay practically upside down in the drivers seat and get my head and both hands under the dash in order for me to get it to separate. I suppose removing the drivers seat would certainly be easier/roomier, but I wasn't up for that challenge. The black and gray subwiring harnesses will come with it - all as one.
Once you have it disconnected, the black and gray subwiring harness will come out. You'll have to gently pry in between each of them with a flathead screw driver to lift it over the tab on the ignition switch. If you look at your replacement I.S. you'll see the little tab I'm talking about. These are easy peasy in comparison to separating the unit under the dash. It's a bugger.
Good luck.