It does not look like you have a lot to work with at all, but this is one of the few applications for which I would use vise grips....try to grip it with the grips.....if you have, or can borrow or rent a slide hammer, hook the vise grips and not hard, but sharply "shock" it with short frequent slides of the weight and see if it works...I offer this in the event that the tapping with a small chisel or a drift r punch does not work...that key should be pretty soft, so I don't think that a brass hammer would be effective...when replacing that key use a new one and maybe apply some Thread Eze....it is a product that has graphite in it ..Permatex makes a product similar to it , I think it is just called anti seize compound...that will help if you have to do this again in the future
Transmission fluid mixed with a small amount of acetone will help as a penetrant
Good luck and let us know how it went...it would be interesting to know what worked
Transmission fluid mixed with a small amount of acetone will help as a penetrant
Good luck and let us know how it went...it would be interesting to know what worked
