Are these actually replies to the question??? I believe he asked how to do it. Well I would say google it if your tooo lazy (making this post instead of searching for the answer first, which the answer is here in other threads here). But to save a little time, I go and kill all zombies exept one on round one, then I run the bus route backwards. I arrive at town after being extremely carefull to keep a grenade or two... open the bank and blow the vault door with a grenade. The reason I do this right away is that you have to hold the button to deposit money (inside the vault, enter the door, stop, turn 180 degrees [so behind you], and the deposit
is on your left).
So, later on in the rounds it is advised that you have a permanent turbine or a friend or something to help give you the time you need to deposit (or just be reeeeally fast).