We will need a letter of authorization from the owner of the car/house/office. If you cannot provide identification, or authorization we will not help you. I am sure the other car, home and office owners will appreciate your cooperation.
Clarification, Changing locks is taking the whole lock, knob/lever, latch and strick and replacing it. Rekeying a lock is taking the existing lock cylinder (leaving the rest) and changing it so that your existing key will no longer work and a new one will. Note, most of the time you will just want your locks rekeyed.