With my car on four jack stands, I had to improvise a tool set with a regular 14mm wrench and gearwrench hex-bit on the second/third pictures. It fits in the space, but required me to flip the wrench side to barely have room to loosen and tighten. I wish I had a 14mm flex head ratcheting wrench at hand. So, next time if I have to do it again in another 40k or so. I will get a LONG flex head ratcheting wrench (fourth picture).
Of course, there is no freaking way to fit a torque wrench to tighten it BMW specs. But I think as long as it snugged tight and probably give another 30-degree turn should be good enough. Or, if I want to be more precise, I can use torque wrench extender and recalculate lb-ft.
A couple of other things during front differential change:
1) there are different views on how much we should fill in front differential. FCP told me 600ml, some document says 400ml and some Youtubers said fill till spill. In my case, I drained just a little short of 400ml and pumped in 700ml without spill. My guess if I gave it one more pump, it may start spill. The fluid does look dark but did not seem to have metal shivers of any kind. The replacement is for my peace of mind.
2) To reach front diff, I need to remove underbody reinforcement plate. I know I am supposed to renew the hex bolts with new ones. But I did not have new ones in hand. Last week I had a starter recall performed at a nearby dealer, and they replaced the bolts at the time. Saved me from buying 10 bolts at $6 each
Thanks for posting your process!