Look close at that pic and specifically at the further away bolt holes, the circles around them. Those are light pressfit bushings that the long bolt goes through, they pull up really tight when the bolt is tightened and then the alt essentially becomes locked in place to be part of the bracket. The task there is to pry or whack the alt without damaging it to slide those inserts back out a slight bit, then the alt will fall right out.
Fords have used that method for years; it holds alts in place really well. Make sure the new alt has the inserts pressed out to be even with the rest of the leg casting or the alt may not fit down in place. It will be super loose but the bolts pull those back up tight to tighten the whole thing up. I use a pair of vise-grips slightly offset to press the inserts back out.
Last edited by amc49; 10-19-2018 at 02:14 AM.