You would have to remove the entire intake manifold, then take it apart to get at the lower intake part. To remove the valves, you have to remove 12 Phillips head screws (2 each) from the butterfly valves, remove them and slide the shaft out of the casting, then seal up the hole where the shaft entered the casting.

I haven't heard what a failing one sounds like, but from all indications, it would make a rattling sound.

The new piece is identical in every regard to the original piece, but it has better bushings that supposedly won't fall apart/into the engine.

I used to live at Wyoming and Candelaria in ABQ. Loved that town.

John B.