were the zombie hangs on shi no numa throw a grenade underneath him until his feet get caught on the fence behind him.
when that has happened wait a few seconds and he will fall.
once you have enough money open the gate to were the zombie has fell.
DO NOT TOUCH THE ZOMBIE
go behind him and sit in the corner and if you look the zombie will be bouncing then when the zombies start to come round the corner when they touch the zombie on the floor it should bounce and kill the zombies that touch it.
be careful though because the windows and stares beside you still let zombies in that can kill you.
thanks for reading hope this may help you +rep if you really want thanks