Once you have at least $7 in your Bank, you are eligible to cash out. All cash outs are handled via PayPal, which is free and easy-to-use. Tap the Bank icon and follow the on-screen instructions.
If you don't have a PayPal account, you can create one at PayPal.com. If you enter an email not in use with an existing PayPal account, PayPal will send an email to that address that prompts you to create one.