Here is a quick guide on how to send a ring tone to your cellphone via email. Keep in mind though, that other methods are much easier. You can use: USB cables, Bluetooth, iTunes, ect.
1. Create a free account at Brinked.com
2. Click one of the download links on the ringtone page you want.
3. Create a new email with the ringtone as an attachment and send the email as a text message.
Here are the email address needed for different providers. Replace 1234567890 with your cellphone number, no spaces, area code first.