Hard Reset SAMSUNG Galaxy Grand Neo Plus

First method:

1. At the beginning remove the back cover and the battery for a couple of seconds. 
2. Put the battery and the cover back in. 
3. Now press and hold together:  Volume Up + Home button + Power button, until you see Samsung logo.
4. Then select from Recovery Mode menu "wipe data / factory reset" using Volume buttons to navigate and Power button to confirm.
5. Next choose "Yes -- delete all user data" to confirm whole operation.
6. After that select option "reboot system now".
7. Well done!