Answer to "How to replace the back glass (heart rate monitor)"The glass on this particular watch cracks due to the strong magnet used to secure the watch to the charger. I too have this issue and am looking at an otherwise brand new Huawei paperweight sitting on my desk. The watch functions fine except for the heart rate monitor which cannot read correctly due to the cracked glass. I got in touch with Huawei and they wanted me to send the watch in to get it repaired for a fee. I feel that because this is a design error, they should replace the glass for free. I'm out of one hundred dollars. Might have to take the loss on this one. I did get a Moto 360 second generation for 50.00.