On my WP8 Nokia phone, I have received a audio file ring tone in an email and in a text which I sent to myself from my old phone.
How do I save it to be able to use as ring tone?
Technically, you should be able to just "Save as ringtone" when you tap and hold the attachment:
To add a ringtone from a text message
1. Tap and hold the ringtone file, and then tap Save as ringtone.
2. Rename the ringtone, if you want to, then tap OK.
If your phone doesn't give you that option, then it's possible (probable) that the file isn't in a format that WP8 supports - WP7 for example only supported .wma and .mp3 formatted audio.
Alternatively, you can try to do it from your PC. Ringtones on WP8 need to be saved in the
Ringtones folder on your phone there are further details on this howto:
First the file you want to use as a ring tone must fit the following requirements:
And most importantly the item that most people miss in the linked article is that the genre tag in the song itself be classified as ringtone.
Save it like plain mp3 file and then use Ringtone Maker to transform it into ringtone.
With Ringtone Maker, you can create ringtones from the music on your phone. Simply open the app, select your favorite song and save it as a ringtone. You can cut your ringtone anyway you like, with editing controls that let you choose the start, end and length of your ringtone.
There’s now support for more music file formats: WMA, M4A, M4R, and AAC along with MP3.