Use an iOpener or a heat gun/hair dryer to warm the outer 1/2 inch of the screen. It should be very warm but not too hot to touch or you may cause heat damage to components inside the device.

Use the iFixit Opening Tool to get between the plastic screen and the device to pry off the screen.

The metal spudger may be needed to get between the screen.

The metal spudger may cause more damage to the screen if used with force.