If using Microsoft® Exchange / Corporate sync, the option to turn off screen lock may be unavailable.
From a home screen, tap Apps (located in the lower left).
From the Apps tab, tap Settings.
From the Personal section, tap Lock screen.
Tap Screen lock.
If presented with "This device does not have a Google® account associated with it. If you forget your PIN, it cannot be sent to you and a factory reset will have to be performed to recover the device.", tap Add Google account now to setup the account before proceeding. To proceed without setting up a Google account, select Continue.
If presented, enter the current PIN, password or pattern.