1. Turn off the phone completely.
2. Press and hold both Volume UP (and HOME) + power on the phone.
3. When Android Recovery menu screen appears release all keys.
4. Navigate and highlight wipe data / factory reset using the Volume down key and press power.
5. Navigate and highlight again to Yes -- delete all data and press power.
6. All data will be lost! Before doing a hard reset backup all important data.
After hard reset is done select Reboot system now. Press power to reboot the phone.
{Make use of|Employ|Work with} Samsung Galaxy S6 {Back-up|Back up} and reset function
{Mind|Brain} to Settings > Backup and reset > Factory data {reset to zero|recast}: Reset settings to the factory default values and delete all data.
The device freezes or has fatal {mistakes|problems}
If your device freezes or hugs, you may need to close applications or reinsert the battery and
{change|switch|convert} on the device to regain functionality. If your device is frozen and unresponsive, press and
{keep|carry} the Power button for more than 8-10 second to reboot.
If that is not solve the problem, perform {a manufacturing plant|a manufacturer|a stock} data reset. On the Applications
screen, tap {Configurations|Options|Adjustments} -> Backup and reset -> {Manufacturing plant|Manufacturer|Stock} data reset -> Reset device -> Erase everything. Before {executing|undertaking} our factory data {reset to zero|recast}, remember to make {backup|backing up} copies of all important data stored on {the unit|the product|these devices}.
See hot hard reset Samsung Galaxy S6
More.......... http://www.hard-reset.com/samsung-galaxy-s6-hard-reset.html
