How do i change my htc text tones (alert) to mp3

To add other sounds to your notifications list, you will need to get to your SD card.

On your SD card, you will need to create a directory titled media. Within the media directory, create a folder titled audio. Within the audio directory, create a folder titled notifications.

Place any .mp3s or other sounds into this notifications folder. Unmount the SD card. Reboot your phone. When you go to Settings > Sound & display > Notification sound, you should see all the newly copied files on your notification list.

Good luck.