SAMSUNG G906S Galaxy S5 LTE-A How To hard Reset

First You Should Backup your all impotent data than remove sim card and memory card.
1. Turn Off Your Call Phone Press power key.

2. When your device is fully turn off press and hold together Volume Up + Home + Power Key Until Show Samsung logo on screen.

3. when show Samsung logo on screen release all keys.
4. Now Highlights This option "wipe data / factory reset" use volume button to scrolling and power button to confirm.

5.Than Select This "Yes -- delete all user data" Again Pressing Power key To continue 

6. last step you select this "reboot system now" confirm it pressing power key.

Done  
2nd method 

1. Pressing power key to turn on your device. 
2. Than Tap Settings  > User and Backup > Factory Data Reset.
accept all information on your device screen.
Done