I’ve taken them apart so many times to change lenses and now to clean those pieces of glass. It’s pretty easy, Doable in about 20 minutes.
There are two silver screws on the bottom that have to be removed. Bottom comes off first.
There are no screws on the back, clips detach with some outward force on the sides. Careful not to tear wire for speaker in the back panel.
Black antenna wire with gold connector is removed, just below it is speaker connector that needs to be removed for back to fall off.
There is another screw in that little white tube just below left the micro usb port. That has to come out so that the midframe and circuitboards can be removed. Careful not to damage antenna at top left stuck to side of case.
Frame comes out and the little black and red connector needs to come out at top left of this photo. This power for the camera I think. There are also 2 black screws connecting the circuit board to the midframe that need to come out. Once these are removed the 1st circuit board is free. but still attached by ribbon cable to the other boards.
I don’t have very good photos of the back circuitboard but it also has 2 black screws that need to come out so you can get to the sensor and lens. This is a view with the back circuitboard removed. The sensor board is the only one left on the frame. The two black screws at the outer edges of this board remove it from the frame. There is a flip up ribbon cable connector and then this is completely free.
Lastly, there are two screws towards the middle of this camera board that release the lens from the sensor. This is where that little piece of glass is located, This is a view of that last board. There is a foam gasket with that little glass filter resting on top between the lens and the sensor. Trickiest part is keeping everything in place while you screw it back together. I usually place the lens on top in alignment with the middle two screws, pinch the board to the lens and flip it over to feed the screws back through the board. Magnetic screwdrivers are a lifesaver.
Hope this helps a little.