How to set PIN lock in Samsung Galaxy S5(SM-G900H)?

a). From the home screen, tap on Apps as shown below :

b). Tap on Settings and then tap on Lock screen as shown below :

c). Tap on Screen lock and then tap PIN as shown below :

d). Enter the numeric PIN that you want to set and tap Continue as shown below :

e). Enter the PIN again to confirm it and then tap OK as shown below :

Samsung Galaxy S5 is now secured with PIN Lock :