DAITEM WIRELESS INTERCOM how do I change entry code?? Help!

[Gagobaa]

    Using your intercom handset open the flap and scroll through the menu to delete the old code. Then scroll through again to add a code.
Stand next to the gate with your handset and when you press ok on add code it says wait.
Add the new code and done.
The manual showing how to do it all from the gate didn't work but using the handset method stood at the gate was easy.