Unless you're confident in your ability, this is best done while going for the Revenge ending as you only have to play through half the game.
Play on easy action level and use the unlimited machine gun to kill enemies fast. I find the Closer (the tall enemies with the meat arms) are the most dangerous as they're pretty quick and don't flinch easily so try to run away from those.
I took about 4 or 5 hits and only had about 100 damage so you'd have to take a fair amount of hits to break 500.