There are 6 T6 Screws surrounding the edges of the frame. 2 are on the outside, 2 are under the battery, and the final 2 are under the water resistant silicon flaps at the top of the device.

Note the 2 Phillips screws here. They are a PH1 and secure the silicon flaps to the case. They can be removed to make things easier, but it is optional.

Using your T6 screwdriver bit, remove the 6 T6 screws and set them aside. They are identical and do not need to be kept sorted.