In order to hard reset a Nokia X, you should perform the following steps.
Remember! Hard reset will delete all the data on your device; pictures, contacts, messages, apps and more.
Nokia X device will be brought back to the default configuration of a brand new device.
1. Start by powering off the phone. Then remove its battery, wait a few seconds and put it back in.
2. Next, press and hold the Volume Down and Power buttons.
3. Select the wipe data/factory reset - use Volume buttons to navigate the menu and Power button to select the option.
4. Next, select Yes and Reboot System Now.
5. Phone will now reset and restart. Done.