steering coupler removal

I haven't seen the split pin that was tapered. ( the roll pin at the top of wheel locking columns is tapered ). The split pin will drive out from either end but I've always centered the steering gear first so they master spline is on the top. That places the split pin to the fender side. Proper pin drift and a hammer.
That pin should be hardened steel too and very difficult to impossible to drill out. Just drive it out. I drop the steering column but not so far as to cause a bind at the coupling. I stack shop manuals in the drivers seat under the steering wheel to get the angle I want. Then I can use a ball joint splitter ( pickle fork ) to move the box coupling off the gear box.