It is not very difficult for us to change the lens of a Gopro Hero 4. Here are the steps which could help you get your lens changed in a few minute without breaking anything.
Firstly, remove the outer ring by carefully prying around the edge using a small flat head screw driver or a flat plastic opening tool. Loosen the clips on the edge then pull the faceplate off. Using the tweezers to lift the faceplate from the rest of the device and using a cross screw driver to remove the screws
The lens is protruding from the top of the metallic base once the outer ring was removed,. Use a wrench to clamp the lens firmly and gently to stop it from slipping, and turn the wrench slowly in counter-clockwise motion while holding the camera with another hand meanwhile. The lens was glued but remember that do not use excessive force, until you hear a crispy cracking sound, the glue break off and you can keep turning the lens gently.
Once the lens was removed, we should clean up the residues of the glue carefully firstly. Making sure the sensor and the lens mount are no dirt or dust. Replace the lens with your new one, carefully align the jaw screw, then twist tightly clockwise to ensure the lens is not be damaged. Calibrating the focus, when it is done, hold the lens firmly in position and use a small flat head screw driver to turn the small lens collar to lock the lens against the mount and keep it flat to the sensor. Turn on the action camera and start to shoot sample picture. Review the picture quality carefully and make any necessary adjustment. Once you're satisfied with the quality, re-install the rubber ring and protective back cover and affix them using glue. Your new lens has successfully installed on your Gopro. &
Add: 4th 313 Room,Liling E-commerce Industrial Park ,Hunan Province, China