Steering coupler question

I need to replace the steering coupler in my car. Is there any way I can get away with doing this without removing the steering wheel? Is there an DIY writeup somewhere?

Say I want to remove my steering box to replace a couple washers. Any way to do it without removing the wheel? I say this because my wheel locknut is far locked and will NOT budge. It is an AMG wheel so there's an aluminum allen locknut in there which is chewed up from previous owner's attempts so I gave up trying to get it off. One day I'll probably drill it out, but with 80's AMG steering parts being impossibly hard to find, I'll live with the wheel on the car.

Thanks!