Kenneth Cole combination-lock briefcases provide a level of security for your important documents. Naturally, it would defeat the purpose of the lock to allow changing the combination while the briefcase is closed, but if you know your case's current combination, it's easy to change to any one you'd like.
Open the briefcase. If it's a new briefcase, its default combination will be in its owners manual.
Locate the reset switch on the inside of the case, behind the lock. It's a small button and it's not designed to be conspicuous, so a flashlight may be helpful.
Press the reset button with a ballpoint pen, and keep it held down as you turn the number dials to the desired combination. When you release the reset button, the dial's current configuration will be your new combination.