Changing the code on this unit is done from the inside. Behind each button on the inside of the unit is a disk with an arrow stamped on it. When first received the arrows will all be pointing the same way, you need to turn the disk 180 degrees on each number you want as part of your code so the arrow is pointing the opposite way to the start position. These numbers should then be set as your access code. For further assistance there is a
User Guide available on the website to download.
Phil R