Hi,i’m going to show how to  hard reset motorola xt1511.

1. Power off the mobile phone completely
2. press volume down key+power key at the same time
   
3. fastboot mode appears
   
4. scroll down by using volume down key and select with volume up key
5. auto reboot mobile and mobile goes to recovery mode
6. when android logo appears on screen,press power key then press 1 time volume up key
   
7. recovery menu appears
   
8. select wipe data/factory reset with power key
9. select “yes–delete all user data”
   
10. it will format all user data