The W116 brake booster is a bxxxh to remove/install, but you don't need to remove the dash. It is just in a very busy space on the firewall and the bolt for the upper suspension arm is in the way. It will take some contorsions , but it come off in the "normal" way. The 4 nuts under the dash are a real treat , as well. You can't even see 1 or 2 of them. Best advice, IF you need one, is to get a rebuilt at Advance Auto or Autozone for about $100. I got a W126 booster out of a boneyard, and I was lucky, but it's not worth the hassle - get a rebuilt one.

Rick

__________________
80 300SD (129k mi) 82 240D stick (193k mi)77 240D auto - stick to be (153k mi) 85 380SL (145k mi) 89 BMW 535i 82 Diesel Rabbit Pickup (374k mi) 91 Jetta IDI Diesel (155k mi) 81 VW Rabbit Convertible Diesel 70 Triumph Spitfire Mk III (63kmi)66 Triumph TR4a IRS (90k mi)67 Ford F-100 (??)