You’re going to need to buy a screwdriver, remove the PC case, find the slot for your CD drive, install it in that spot. Then you’ll put everything back together inside the PC Case. There are tutorials on YouTube if you want more help with this. Some people also call places like Geek Squad or something before they do this at home – I couldn’t get my CD Drive installed and I needed some assistance – so call someone who’s done it before and get all their advice. If there are too many pieces or it doesn’t seem like something you can figure out on your own Google has great resources.