Just keep playing zombies, get used to the map and where the zombies are coming from and where's the best place to stay etc. Try not to attack George as he will only make it harder for you, if he does get angry lead him into the ice water to cool him down and he will stop attacking you. All the zombie trophies are luck based so there's not step by step guide to getting all the trophies. If you happen to get a Scavenger in the random weapon box then get the "Shooting on Location" trophy, or if you happen to get the V-R11 then get the "Stuntman" and "Quiet On The Set" trophies. A really good tip I can give you is at the end of every round try and get a crawler to be left so you can go about getting trophies without hundreds of zombies attacking you. Good luck and I hope this guide helps!