Changing a luggage lock combination is a good idea for several reasons. The preprogrammed combinations that come from the factory are easy to guess. A personalised combination prevents strangers from opening your luggage. It is also easier for you to remember. You should change your luggage lock combinations as soon as you get a luggage lock.
Unlatch the luggage lock. It will come from the factory with a preprogrammed combination. This is usually something simple like 0-0-0-0, 1-1-1-1, or 1-2-3-4. If the lock does not open, look around for a piece of paper from the manufacturer revealing the combination. If you can't find one, contact the manufacturer and ask what their default code is.
Prepare the lock for a new combination. On an attached lock on a piece of luggage, you do this by pushing the unlatch button all the way open until it can't go any farther, then holding it. You do it on a portable luggage lock by turning the locking hook so that it is pointing away from the hole and pushing the hook down into the lock.
Decide what your new luggage lock combination will be. Make sure that it is something you will remember. Avoid sequential numbers like 5-6-7-8, or repeating numbers like 5-5-5-5.
Dial up the new combination on your luggage lock. Make sure that the numbers line up on the line or in the window. It is a common mistake to be looking in the wrong place when dialling up the numbers.
Undo the lock mechanism. On an attached lock on a piece of luggage, you do this by simply letting go of the latch button. On a portable luggage lock you pull the lock hook up and turn it around so it lines up with the hole again.
Use the luggage lock. The new combination is set.
If you lose the combination you won't be able to go to the manufacturer to find out what it is. Your only option will be to go through all the numbers until you come across it.