export all itunes files.

so, i just had my laptop repaired. nearly everything was luckily saved except some easily downloadable programs and my music files. luckily, i still had them on itunes.

but now i have come to a problem. i have about three hundred+ mp3 songs in my itunes library that i do not have on my computer in my documents anymore. i need them to be able to back them up, but i do not know how to save them. i followed a guide on this site, but all it did was save the music i purchased; not the music i downloaded personally. could someone help?