How do I add a plug to a hard-wired garbage disposal?

My garbage disposal is broken and I ordered a new one online. Stupid me, only after ordering it did I realize that my garbage disposal is plugged into the wall and the new one I ordered has a hard-wire set up (no plug). So apparently I need to add a plug to the hard-wired disposal so I can plug it in. Can anyone tell me (or refer me to a website that can tell me) how to do this? I'm not an electrical engineer, but I'm competent enough to follow straightforward instructions. I really appreciate the help!