hey
all you have to do is upload the mp3 to this website

http://www.mymp3tone.com/index.aspx

then you can edit it online, and save it.using WAP you can download it
to your mobile fone and there you go!
its free and you can edit it(shorten , etc.).besides, thers no
installation or anything required.

best of luck!
(i do hope your fone is WAP enabled)