On the inside or outside, just turn the knob (or lever or thumbturn). You don't need to enter the code.
On the inside, just turn the turn knob or thumb turn to retract the deadbolt. You don't need to enter the combination.
On the outside, press the "C" button first (or turn the thumb turn as far as it will go). This will clear out any previous button presses. Then enter in the code and turn the knob (or lever or thumbturn).
The Lockey Key Override System (KOS) is a separate product that lets you lock and unlock these locks using a key OR a combination. This is really great if you have multiple locks with different combinations.