How can i re-set the combination for my lock?

Bolt cutters

They are too cheap to worry about fixing.

I gotta agree with Dr. Bill.

I don’t like throwing things away and would rather fix it.

I presume this is a lock where you, yourself, set the combination and you forgot what you set?

The only way you can get a lock combination from the company is by proving you purchased the lock, so if you have the receipt saved and have access to the lock to see the serial number on the back, there may be a way to get the combination and thus keep using the lock.

Otherwise, it’s best to take a tool to it. It simply takes too much time to brute-force a lock, such that it’s more value for your time to simply cut it off and buy another one.

To prevent this from occurring again, please set up a combination remembering system. This can be as simple as a piece of paper in your filing cabinet which has the combinations written down (but don’t title the page “MY SECRET LOCK COMBINATIONS” – you don’t need to be really stealthy, just don’t be blatantly obvious). My father had a nice system using a reinforced hole-punched tag with the lock combo on it, the paper remained hooked onto the lock unless the lock was in use, in that case the paper remained on the lock shelf with other locks and papers.

If it is an older 3 digit master lock you can figure out the combination in about an hour. It’s a great party trick. You can look up the method yourself on the ‘net. (Uses modulus arithmetic Mod(4) )
If you have the time, try it. Otherwise pitch it, and get one of the new ones which are more difficult to crack.

If you are talking about the ones with the dial on the front, you can crack them with the following article

If its one of the ones with four digits on the bottom, you’re probably SOL.