To set a password on a Samsung Galaxy S6 phone, tap Settings on the home screen of your phone, select the Personal tab, and tap the Lock screen and security option. Once on this page, select the Screen lock type section, and choose the Password option.
Enter a password with four to 16 characters; one of these characters must be a letter. Enter your password again to confirm it. Alternatively, you can set up a personal identification number and use it as a pass code. The PIN must contain four to 16 digits. To set up a PIN, select the PIN feature in the Screen lock type section.