1. Download the song from a music streaming service. Many streaming services, such as Spotify, Apple Music, and Pandora, offer "Crazy Train" for download. Once you have downloaded the song, you can listen to it offline whenever you want.
2. Transfer the song to your phone from your computer. If you have the song on your computer, you can transfer it to your phone using a USB cable, Bluetooth, or a cloud storage service such as Google Drive.
3. Buy the song as a ringtone or alert tone. Some mobile carriers offer "Crazy Train" as a ringtone or alert tone. You can usually purchase these tones through your carrier's website or by calling customer service.
4. Use a third-party app. There are many third-party apps that allow you to download music from the web. Some popular apps include TubeMate, Snaptube, and Videoder. However, be aware that downloading music from third-party apps may be illegal in some countries.