N82

Download the mp3 or aac file to your computer and connect the phone to the PC with the USB data cable.
Start Nokia PC Suite, a message will appear near your desktop clock that the phone is connected and its model will be shown.
Go to My Computer and open N82 device.
Open the Memory card explorer and copy the mp3 file into any folder on the memory card or in the phone memory.
You can assign the sound to incoming voice or video calls, message, alarm and email alerts in Profiles.

or

just connect your mobile in data transfer mode, right click on the file and send it to memory card.