You shouldn’t need a crank extractor. It has an aluminium top cap with a 10mm hex key. Leave that in place. Then an aluminium screw with an 8mm Hex key beneath. You should remove it my unscrewing the 8mm hex against the top cap which works as a puller. If you do remove the aluminium screws also remember to remove the steel washer because that will stop you from getting your crank extractor to push against the shaft.
Try it again with the washer removed and you may have enough thread left to pull it off. Failing that, boiling water and hitting.