Now master reset your Samsung Galaxy with two best methods

1. Master reset: Samsung
Galaxy S5
With Two Effective Ways

3. First Method
• Back up data on the internal memory.
• From any Home screen, tap Apps.
• Tap Settings.
• Scroll to 'USER AND BACKUP,' then tap Backup
and reset.
• If desired, tap Automatic restore to clear the
check box.
• If desired, tap Back up my data to clear the check
box.

4. • Tap Factory data reset.
• Tap Reset device.
• If you have screen lock turned on, enter your
PIN or password.
• Tap Continue.
• Tap Delete all.

5. Second Method
• Back up data on the internal memory.
• Turn off the device.
• Press and hold the following three buttons at the
same time:
– Volume Up key
– Home key
– Power key.
• When the phone vibrates, release the Power key
but continue to press and hold the Volume
Up key and the Homekey.

6. • When the Android System Recovery screen
appears, release the Volume Up and Home key.
• Press the Volume down key several times key to
highlight 'wipe data / factory reset.'
• Press Power button to select.
• Press the Volume down key until 'Yes -- delete
all user data' is highlighted.
• Press Power button to select and start the
master reset.
• When the master reset is complete, 'Reboot
system now' is highlighted.
• Press the Power key to restart the device.

7. For Related Topics
Samsung Galaxy S5 Manual