The fins of your flywheel sit on a flange that extends out past the magnet faces doesn't it?
So you set the air gap the exact same way- just the methodology has to change.
A business card cannot be inserted from the top with the saw on its side- so it must be a card trimmed to the height between case and flywheel flange- holding bolts of coil loose- card slipped in between coil and flywheel with the magnets away from the coil- card held in place and flywheel rotated until the magnets are in line and pull the coil onto the flywheel face.
Tighten bolts, rotate magnets away from coil and the card will come free- the circumference of the flywheel is not a perfect circle- the magnet area is slightly raised- so rotate past that and the friction should be lost that is holding the card allowing it to be pulled away.