From a linux command prompt, do the following:
MyWmaFile.wma is the file you want to convert into an MP3 called MyMP3File.mp3
first rip the wma into a wav file by running this from a terminal window:
mplayer -vo null -vc dummy -af resample=44100 -ao pcm:waveheader
MyWmaFile.wma && lame -m s -V 3 audiodump.wav -o MyMP3File.mp3
(put above on single line)
doneskies.