Front diff replacement

My front diff is humming. It's not low on oil but I can feel my gears are very worn. I've got 212,000 miles on my 03' double taco TRD and I pull a car trailer, boat trailer and horse trailer and plow with it so I expected this...actually sooner.
My rear end just went through the same thing so I did a entire hub to hub rear axle swap for a 100,000 unit. Took only a day being a conventional rigid axle.
The front axle has independent suspension and does not look like a simple drop. Some parts of the suspension look to be bolted to the frame.
I don't want to just rebuild the pumpkin since the whole unit is 10 years and 200,000 plus miles old.
I can't seem to get a factory manual so I don't know the unit well enough from just eyeballing it to tell the auto recycler/used parts guy what I need.

What should I replace? How difficult is this going to be? There isn't the wide open room like the rear axle install gives you.
Thanks David