Since the iPhone 8 later, Apple phone back cover are used glass back cover, which is different from the previous aluminum back cover, aluminum back cover fall will only deformation, but the glass back cover broken you have to replace the new back glass. Usually the back glass is not easy to replace, and need to pay an expensive price. So the screen should be protected, while the back cover glass should also be carefully protected.
But how to replace the back glass alone without replacing the metal bezel back cover? The best way at the moment is probably to use a laser machine to help.
We use iPhone 11 Pro as an example, first, the iPhone 11 Pro screen face down in the laser screen remover clip strip position. In the computer to pull out the corresponding drawings, the role of the drawings here is to make the laser machine according to the path of the drawings burn to avoid laser damage to important parts of the iPhone.
After the back glass has been laser burned to achieve the adhesive removal effect, the iPhone 11 Pro back glass becomes transparent and the important internal parts are almost exposed.
At this time with a thin small iron sheet can simply remove the broken glass, the back cover glass is cleared to remove the machine to take the lens, etc., and finally replaced with a new cover. 
Although the laser machine can easily take down the back cover glass, but if you do not pay attention to the method is unable to achieve the best results, so in the removal of the back cover we also need to pay attention to some details Drawing to be very accurate, if the drawing accuracy error, will burn other parts, or part of the adhesive does not completely melt resulting in difficult to remove the situation, in addition to parameters to be set, including laser power, burning speed, etc..
But now that you are using the back cover to protect the mould, it will be easier for you to laser burn the glass
