I'm not sure I understand your issue, but my split column has two of those rubber eared bushings -one on the bottom half and one on the top (either side of the coupler). Somehow, the two shafts must be separated and the coupler removed. If memory serves me, the coupler cannot simply be slid far enough to allow the bushing to enter. I had a big problem thinking there was a stepped collar on the shaft but it turned out to be remnants of an old bushing. A steel sleeve remained fixed onto the shaft as if it were machined there. (The new bushing had no steel sleeve.) With the shaft removed from the housing, it was possible to remove the old sleeve/bushing remains and then slide the new one in, after the shaft was back in the housing (outer tube).
Listen, It's perfectly simple. If you're not getting your hair cut, you don't have to move your brother's clothes down to the lower peg. You simply collect his note before lunch, after you've done your scripture prep, when you've written your letter home, before rest, move your own clothes onto the lower peg, greet the visitors...