Is the drive only leaking gear oil or are you losing hydraulic oil as well ?
If only leaking gear oil you have the option to replace the duo cone seal without removing the final drive housing from the machine. May save you from fighting a bunch of rust in the frame. Referencing the parts screenshot below.
Drain the final drive oil .
Remove the planetary pinion assembly #25, gear #17 , shaft #35 and planetary pinion assembly #16.
Drive the dowel pin #13 (that locks the nut to the ring gear) inwards until it is clear of the nut #12.
Support the drum #6 and sprocket #7 before loosening the nut.
You will not likely need a socket to loosen the nut when disassembling a couple of raps with a bar will usually get it loosened. (You will definitely need to fabricate a socket to torque the nut to spec when going back together).
Spin off the nut and remove ring gear #11.
Remove drum , sprocket , (2) bearings #4 and duo cone seal assembly # 5.
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https://partscatalog.deere.com/jdrc/sidebyside/equipment/63405/referrer/navigation/pgId/2950 .