+1 to the notion that this isn't really possible (or not without a bunch of bodywork...).
The bumpers are NOT a straight swap - the front fender joint is totally different between the pre and post facelift cars.
There's been a few thread about this...
https://xoutpost.com/bmw-sav-forums/...-question.html
https://xoutpost.com/bmw-sav-forums/...per-06-x5.html
mrbmwx5 has managed to fit the 4.6isS spoiler to a facelift bumper...
https://xoutpost.com/bmw-sav-forums/...ift-3-0-a.html
*edit* BTW, your post is confusing - the title says you have a
pre-facelift 4.4i but the post says
facelift 4.4i.