No shims adjustments on MF 35 WITHOUT differential lock.
Adjustment on pinion is done by the adjustment nut, and a torque wrench or similar.
Of course you need to take the diff. assembly out of the center house, place it on the workbench and do the ring gear swap there.
You need a friend to help you with the ring gear. You see, first you need a torque wrench, and then you need a real big scredriver. When you study the bolts you will see the size you need.
I don't have such a big screwdriver, so I had to make it from a large truck leaf spring clamp, and harden it. This screwdriver is around 24 inches long end to end, and a 90 degree angle in the middle so I can hold it tightly.
It is really nuts how much power you need to hold it. It was much easier of you could use a regular pipe or so, but there is other parts on the diff. that goes into the valley between the ring gear tooths and the diff housing so it is almost impossible as the construction is made.
You need both hands on the screwdriver, + the force of your upper body to hold it in place. It is hard to hold the diff. house in place, unless you have a real large wise.... I was not close to it.
I will not recommend you to put the ring gear directly in the wise, it is extremely hard, just bang it with a little screwdriver handle and you will hear. Like a little church bell. A little crack, and the fun is gone !!!
If you fail on this, please remove the nuts from the ring gear right away before the Loctite gets a chance to lock. Once locked you need to heat them with a Acetylene / Oxygen flame and never use them again.
This Loctite is a strong type, and fast too....
Have no comment about a complete diff. housing price, + pinion. Remember, never change only the ring gear, There is a code on both ring gear and pinion so you can see the match.
I paied US $190 + sales tax for a used ring gear and pinion. They were very fine, and not worn to much.
Hope this helps.