So I have a 2006 xc90 4.4. Overall it's in good condition, I do the regular maintenance items: oil, filter, ect. I've been getting the charging system warning occasionally and it seems to be happening more often as of late so I figured I'd proactively replace the alternator before it fails completely 145k on the odo. I found/read the guides, have the tools and have the ability. So I went and tackled the job this weekend....what a pita!!!! This is by far the worst/hardest time replacing a part I've had in my life. In the past I've fully rebuilt ford 5.0 and 4.6s, done engine swaps on mustangs, worked on Audi's, done press in wheel bearings, transmission swaps ect. Getting the old alternator out and new one (bosch) in was insanely difficult. It took me around 4 hours to get the old one out and another 1-2 to get the new one in and reassemble everything. Tire off, ball joint off, sway bar endlink off, access plate off, axle nut off, axle retaining bolts out, axle out, unbolt the lines in the way, belt off (got a new belt as well), the 2 lower bolts on the alternator were relatively straight forward, the top one is a major pain (budget 20-40 min for that guy), charge cable off, connector off, 1 hour of wrestling, turning, figuring out a jigsaw puzzle you can't fully see later alternator out (remove the heat shield before you pull the old one), then the whole process in reverse.
The worst part of the whole thing is when I got everything back together and went to put the belt on and the idler arm snapped off(the 19mm stud)...of course no one stocks the tensioner so I have one on order. So instead of getting the joy of a hard job completed now I have a disabled xc90 sitting in my shop waiting on a terribly designed tensioner after replacing the hardest alternator I've ever done in my life.

So a word of caution to anyone who attempts to do this yourself...I've seen people quoted $1000-$2000+ to do this job, and as someone who's taken it on it's justified for the high labor cost when it comes to replacing the alternator on a 4.4l xc90.
Luckily this is not needed to be a daily driver although it normally is (I'll have to use one of my shop trucks until the part arrives)

 

Hope you installed the updated cooling duct if it didn't have it.