Did you ever lose your house key or maybe the kids lost theirs. If you have then you know you worry about someone finding it and using it to enter your home. You have a couple of choices, you can replace the entire lock or you can have it rekeyed. The same thing when you buy a new house. Do you replace all the locks or get them rekeyed. I have always replaced all the locks figureing it would be less expensive than hiring someone to rekey them.
Now I find out that you can buy a kit and rekey them yourself and save a bundle off the other methods. If you need to change your lock check out this how to from Family Handy Man and see how you can rekey a door lock by yourself. You will need to buy a rekey kit for the brand of locks you have. For example Schlange or Kwikset are popular brands of locks and if all your doors are the same lock brand you save even more because the kits do multiple doors and you will only need one kit as long as they locks are all the same brand.familyhandyman.com