Assuming that your travel trolley bag has a number lock, you can set up the unlock code by pressing down the release switch, turning the dials to create the desired combination, and releasing the switch. You can lock the bag by changing the combination when the bag is shut and unlocking it by turning the dials to match the unlock code. Most trolley bags come with their unlock code set to 0-0-0 by default. However, if you have forgotten the code, follow these steps to unlock your bag easily within 2-3 minutes.