The application took me about 10 minutes. The manual is a joke for those who can not speak Chinese. The English is translated very deficient. Having tormented by me, but it was easy. For those who can not speak English:
1. clock to clean (Accessories is manigfaltig at)
Apply and adjust 2. Glass
For the adjustment I used a small tool of the mobile phone repair without but it should also work.
Now that the glass on the clock is I can not see any difference in the feel and operation. I would buy me back.