From a Home screen, navigate: Apps icon > Settings.
Tap Mobile Hotspot and Tethering.
Tap Portable Hotspot.
If prompted, review the info then tap OK.
From the PASSWORD field, enter the desired password. If the field is greyed out, tap the switch (upper-right) to turn off . Password must be at least 8 characters, see example image below. Tap Show password to view the entered password.
Tap the left arrow icon (upper-left) to save and return to the previous screen. The new password must be entered on the connecting device.