To set the code on a numeric padlock

Not exactly sure on the one you have, some require a special tool, others can be reset without. Try this, open the lock and rotate the shackle 180 degrees and press down and hold it. Move one wheel one number.

If that does not change the combination then try rotating the shackle 90 degrees hold it down and try again.

If this doesn't work, bring it to your local locksmith and he might be able to get you a tool to reset it.

Believe you may have an American #175 pad lock worth around $10 bucks. if so? it uses a change tool. below is from Americans site

For security and liability reasons neither HPI nor Master Lock Company provides combinations to end users by phone, mail or e-mail. However, if the padlock is not secured to anything you may send it to: HPI-On-Line P.O. Box 1326 El Cajon, CA 92022-1326 with a check for $6.00 each. We will then return the locks to you with the correct combinations. Some may find it less expensive to simply purchase new locks, others may find some locks to be sentimental in value.

Yup, right on the money. I took it to a locksmith and they changed the code for $2 bucks. Not too bad.