Video obtained by the Post shows a man giving a step-by-step “how-to” for hacking Santander Bank ATMs — a scam that has struck across the region in recent days and led to a police chase on Staten Island yesterday, police sources said.“This is the beginning, you put your pin in and everything,” an unidentified man who is making the video states, before pressing withdrawal.“You hit checking,” he continues. “You click $200. After you click $200, you go back. Click other, customize withdrawal. You click ‘choose your own mix.’ Press the $20 option one time. Once you see that 11 you know you lit.”The video never actually shows the man getting $220 out of the machine, but the sounds of the ATM counting the bills can be heard.The scam targets a flaw in Santander’s ATM where people use pre-paid debit cards and withdraw more money than what is on the card, sources said.The multi-state scam was first revealed Tuesday when cops swarmed a bank in Staten Island looking for two scammers, according to video of the incident and police sources.Videos posted online show a large police presence at the bank near Great Kills Park. Police sources said cops had one man in custody Tuesday and were searching for a second.