Oil pump - ZTN

I remove the setscrew that holds the top bearing in. (The distribuitor or magneto already removed.) That way there is no chance it is not screwed out far enough. The gear is held on by 2 woodruff keys.
Then I take a flat punch and tap the shaft upwards a little bit. Maybe 1/8 inch. That's when the top woodruff key hits the crankcase. I go gentle because I don't want to ruin the woodruff key or mar the crankcase.
Then tap the shaft back down. Now there is a gap between the crankcase and the block where I can pry the gear the rest of the way off with a screwdriver or an L-shaped pry bar.
Then just remove the woodruff keys and the shaft comes out the top of the block. Sometimes you have to pretty much tap it all the way with a long punch or bar.

When you put it back you want .0015-.004 clearance between the side of the gears and the crankcase.

Hope this helps!