The link the ChitlinsCC gave you will have all the information you will need.
The main way to study for the exam is through ATLAS. In order to study through Atlas, you need an active GSX (Global Service Exchange) account or to buy Apple Care Technician training. To apply for an Apple GSX account you or your company must have an existing business account/service contract with Apple.
Prices can range (https://www.learnquest.com/schedule-custom.aspx) for classes, please take a look here at Apple's Programs. If you are able to get a GSX account, and you feel comfortable and confident enough to study on your own, it will be a lot cheaper.
You will need to contact Apple directly for step by step instructions on how to set up an account if you do not already have one.