In order to hard reset a Hisense Sero 8 Pro, you should perform the following steps.
Remember! Hard reset will delete all the data on your device; pictures, contacts, messages, apps and more.
Hisense Sero 8 Pro device will be brought back to the default configuration of a brand new device.
1. Power up the phone.
2. Settings > Backup and Reset < Factory data reset.
3. Reset device > Erase everything.