Many of us suffer from a weeping diff.Usually it is the input shaft seal leaking.
There is two ways to do the job.
Either take the differential out or take the propshaft out.
In case the exhaust is already cut somewhere,I would go for removing the part under the differential,disconnect the drive shafts(Torx E14,tightening torque 83NM),remove differential oil(14mm inhex socket),disconnect the prop shaft(16mm socket,tightening torque 70NM),floor jack under the diff,remove the bolt of the front mount(21mm socket and spanner,tightening torque 150NM) and the bolts of the rear mounts(16mm and 18mm socket,tightening torque 105NM).Note that installing the diff,first tighten down rear bolts,then front bolt.
Now it's time to pressure wash the whole thing,just cover the inside of the input flange.
If the exhaust is still stock one piece,has to be dropped completely.Then the propshaft removed.Perfect time to throw a new guibo and propshaft center bearing in...
For both cases,clean the nut in the propshaft flange and mark the position of the nut to the flange(important not to overtighten during assembly because the tension of the nut is responsible for the input shaft bearing)
Remove the nut with the impact wrench(32mm socket) and remove the old locking plate of the nut(replace with new one).
Clean the inside again to mark the position of flange to the shaft.
Use mallet to remove the flange.
I take now a screw driver to pull the old sealing out.Clean the contact surface,oil the new sealing and drive it with a socket with large enough diameter in.
I usually replace also the dust cover of the flange with a new one
Install flange(pay attention to the marks) and tighten the nut to the mark.Push the new locking plate in,use the 32mm socket and the mallet to force it in.
Assemble everything,diff oil in,get a beer...
If anyone is interested,I write a full DIY how to rebuild these differentials as I have one to rebuild in a few weeks...