Do you want to customize your notification tones for your SMS, MMS, IM, or other communication application?
First mount your Android device so that it’s accessible from your computer, the one your your SD card go to media > audio > notifications. This is folder where you store files for use by application notifications.
For ringtones follow the same process media > audio > ringtones is the folder where you store files to use as phone ringtones. I have been able to get my ringtones to work just by placing a ringtones folder in the main directory of the SD card. My recommendation is to try both methods and use the one that works for you.
For alarms follow the same process until you find the alarms file.
If these folders aren’t there, just create them.
Once you’ve reached the correct folder drag and drop your desired ringtones to the appropriate folder.
Now that you’ve completed all the steps above, unmount your phone from the computer and all your added ringtones should be selectable, if they’re not reboot your phone.