Ben Z
Veteran
There's an old story about the guy who calls the furnace repairman to come out at 3AM in the dead of winter. When he gets there he walks around the furnace stroking his chin, then pulls out a hammer and gives the boiler three light taps. The furnace starts working, and the repairman presents the customer with a bill for $400.75. The customer is hopping mad and demands to know what possibly justifies such an obscene bill for three little hammer taps. The repairman replies, "The hammer taps are $0.25 apiece. The $400 is for knowing where, how many times, and how hard to tap."
I don't find any of the rangefinder adjustments difficult. I didn't find it difficult to mill (aka, negative shim) my front-focusing 135 Tele-Elmar. But someone else might find it not only difficult to do, but perhaps end up with a more expensive repair. All I can say is, think carefully and honestly assess your manual dexterity before you jump in.
I don't find any of the rangefinder adjustments difficult. I didn't find it difficult to mill (aka, negative shim) my front-focusing 135 Tele-Elmar. But someone else might find it not only difficult to do, but perhaps end up with a more expensive repair. All I can say is, think carefully and honestly assess your manual dexterity before you jump in.