Turn locking device on back side of phone marked by the rectangle counter clockwise.
Remove battery by grabbing the sides and pulling upward.
Remove back cover by taking out the four, five point star screws indicated in the picture. A 1.5mm flathead screwdriver can be used to remove the screws.
Once all screws are removed the case will easily lift off.
With the back cover removed, the antenna is now exposed. To remove it, take out the phillips screw holding it in place.
With screw removed, gently pull the antenna outward. It should slide out easily.