Depending on your phone, you may be able to change the number of ringtones in a few different ways.
iPhone:
If you have an iPhone, you can go to Settings > Sounds > Ringtone and then tap on the + sign to add a new ringtone. You can also delete ringtones by tapping on the - sign next to the ones you want to remove.
Android:
The process for changing ringtones on Android phones may vary slightly depending on the make and model of your phone. However, generally speaking, you should be able to go to Settings > Sound > Phone Ringtone and then select the desired ringtone from the list. You may also be able to add new ringtones by tapping on the Add button or icon.