Hi peter,

Thanks for the question, Most of our padlocks have instructions on the packaging of how to change the number from the factory setting of 0-0-0-0

if that doesn’t help we also have many videos on youtube showing step-by-step instructions. Just search on youtube for amtech and the stock code ( on the packaging)

If you have thrown away the packaging and do not know the stock code, send a picture of your lock to contact@dktools.com and i will gladly email you back with the link to the correct video.