1， watch a nut on the bolt body core central unloaded， 

2 bolts align the center hole plug in the middle， and then use the nut hold the meter body， 

3 fixed table and then use the nut body， 

4 hour shortest think like buckle buckle snap button in the middle of the hour car 

5 minute on the minute hand car buckle 

6 seconds buckle on the second hand car 

7 battery installation