What do I use to...
 

...change WMA files into MP3?

I use ImTOO Audio Encoder. It's free, and even tho it's supposed to be just a trial version, I've never had any trouble converting anything.

http://www.imtoo.com/audio-encoder.html

:y:

is there a way to make it do more than 2 files??

Foobar2000 is an excellent media player that has a built in converter. If you come across a conversion you want and it doesn't support from the original download, they have plenty of add-ons.

Uhhhh...works for me if I just add them normally.

for some reason it's only letting me do 2 at a time :-\