Yes, the intake does have to come out to replace the housing.
Might as well replace those upper and lower intake gaskets while you are at it ($18ish).
They cause a lot of CELs, codes P0171, P0174.
Don't let it scare you, it's not that bad of a job. I do like to remove the hood when I do them though. The bolts can be very difficult to locate if you aren't familiar with the installation. Here's a good write-up: http://www.explorerforum.com/forums/...4&postcount=33