Changing crankshaft bearings with the engine in the car.
I would bend up a cotter pin to slip into the oil hole, funny angle thing and just rotate the crank.
The cotter pin "flukes" laying across the bearing surface would just push the shell around till it'd pretty much fall out when nearly all the way around.
Just lay the new shell on the clean/lubed crank surface, finger pressure to get it started, the cotter pin/rotate shaft till you can engage the "tab".
Not my favorite job, hoist helps.
@Kern Dog