I've always knocked the split pin out holding box coupling to shaft and removed steering column along with box coupling. And I stated that backward. Unbolt the column first. Stack some books or something in the seat to catch support under the steering wheel. Makes it easier going back together too. I never even considered taking their feckin bottle cap off the box coupling unless rebuilding the coupling itself.
There's a tiny notch filed in the edge of the box coupling marking where its internal master spline is. Some pitman arms have 4 master splines so the arm could go on in 4 different positions. I forget if this is Chrysler, or Ford, or other. You'll need to center the steering gear before attaching the pitman arm regardless.
