Using the plastic opening tool, slightly separate the casing holding the large lens in place.

Separate the casing completely from the inner lens using your hands.

This should release the outer lens and it's immediate casing.

As you separate the outer casing, the lens and digital display box may fall out of their encasement.

Although there are threads connecting the outer lens casing and the inner lens casing, do not be fooled. The outer lens casing cannot be disconnected by unscrewing it.