Mike........you ain't the first one to "spin" a starter Bendix and not gitter to retract. Just hold'er to yer 6"-wire wheel grinder and spinner back. Iff'n it don't go back when holding starter motor left-to-right, flipper so the starter motor is right-to-left. Simple, eh?
And yes, the starter Bendix is held onto the starter motor shaft by a roll-pin. Me? I use a "nail" to punch'er out. Then for eaze of replacement, I grind a "wedge" on end of roll-pin ...and... tapper home. Simple, eh?
And yes, the starter Bendix is "spring-loaded" ...but... you can still gitt the roll-pin to fit with the wedge trick ........Dell