If you have little hands you can pull the ficm and reach back there. Use the socket with a nuckle attached to it then use a 6 inch extension and ratchet it will work. If you dont have small hands pull the turbo.
Snap-on makes a socket specifically to change that style ICP sensor without removing hardly anything. I think you might have to yank the FICM but that's about it. It's a slick outfit.
remove the rear heat shield, its two 8MM bolts and one 13MM. Remove degas bottle, remove ficm. Spray penetrating oil on the the last intake manifold stud to let the top nut that holds the wiring harness ground on free up. pull heat tube off, unplug. Use a cheapy combo wrench, and cut the box end off. climb back under, reach up with wrench, break loose... No more than 15 minutes