There are tutorials on TBN (by the way :welcome: ) as well as I'd suggest getting the tech manual that covers your tractor model would be worth the investment. Torque values and removal procedures are outlined.
Can do one side at a time, although one other thread removed more than necessary, according to the tech manual.
http://www.tractorbynet.com/forums/parts-repairs/84836-4310-jd-rear-axle-seal.html
Also, the tech manual says (for right side):
Need to remove the parts in your way to get at the 8 cap screws holding the axle (final drive) housing to the transmission housing.
That would be the 3 pt hitch arm, wheel, brake spring, brake rod, park brake, ROPS bolts, and gently pry the final drive housing away.
Will need good blocking under the tractor and maybe a way to support the weight of the ROPS.
Might be a real good time to get the tech (service) manual if you don't have one already. Worth it as there are pics and detailed steps.
Here is a schematic from jdparts.com that may help you visualize the task... should be doable.
Items 12 and 13 are the cap screws that hold housing #6 to the tranny. That final drive weighs about 75 lbs according to the book so some support is advised when removing the 8 cap screws.
Here is schematic for 4200 right side.