Does anyone know how to remove this steering cylinder from the Alpha 1 transom plate? I started wrenching on it but I'm not confident I am doing it correctly.

Ayuh,... How old is that thing,..??..??

It looks nothing like the Alpha 1s I've worked on,.....

It is a 1979 Hallett Mini Day Cruiser. I've not had much luck finding photos or instructions online.

that looks more like a #1 drive (pre alpha). would guess that the only thing holding it is the bolt ( or nut) on the left lower side of the pic. I think this is what you have.
https://www.mercruiserparts.com/bam/...79730/28146900