get a file viewer app like astro (or you can do this by connecting your phone to a pc) and go to your media folder which should be in the root of your sd card (if there is not such a folder, create one on the root of your sd card). inside the media folder there should be a file named "audio" (or make one). inside that, create 3 folders: "ringtones", "notifications", and "alarms". now just put whatever sounds you want in the appropriate folders, and you should be good to go