If you have a key that you need copied, you could always take it a locksmith or your local hardware store, where they will be able to copy your key usually within minutes for a small fee. But, what about you enterprising do-it-yourselfers? Is there a simple way to copy a key at home without paying someone else to do it. Actually, there are a few ways to do that. But, keep in mind that key replacement for locks that you don’t own is not only unethical, it may be illegal.