I just did this today and it wasn't nearly as difficult as I thought it would be. Although I had a hole in the smaller tube, I didn't have a noticeable whistle, but I did have the SES light that would not go away.
I didn't remove the cabin filter stuff or the small kick panel thing as it was only a little obstructive. Also, since the smaller tube was already split, I cut it through so I could pull the lower boot off first, then I could work on the smaller piece. It was a gamble to cut it because I had to have the car back together by a certain time for my wife to go out of town. Luckily, I was able to get to it and remove it easily.
I also cleaned the throttle body and the IAC module while I was in there. I cleared the SES light and took it for a drive.
Thanks for the write up!