If its an american bottom bracket,unfortunately you are correct that you have to persuade them out with a hammer.
There is no best thing really, something solid like a bar of sorts(socket extension bar).
I wrap the end of the bar with masking tape so it marks less, doesnt matter how hard you try you get a few dinks on the cups.
Use a good firm hit, then move the bar round a bit and do it again.
Once they start moving it gets easier.
p.s. mind your fingers