I had the turret on a HL1 realigned and all I recall the tech doing was loosening the bolts round the center of the turret and just tapping it with a plastic hammer. It seemed these bolts had enough clearance and that the turret was only gripped by friction, no shear pins or anything.
One time we knocked a turret out of alignment during a tool change and that time we got a Turret Settle error and it would not lock correctly. This time the tech went in under all the covers and re-aligned the connector between the servo motor and the worm that rotates the turret. Apparently the servo indexes a certain number of counts and stops and then the turret locks by pulling back into a dog clutch. If the drive connection slips then the servo does not bring the dogs into alignment. At this time he also did the alignment from the front bolts.