Help to remove DRM on Windows Vista

Yesterday I just bought an audiobook from online store, it was in wma format with a DRM. Problem, i have vista and fully updated media player 11 11.0.6 so i have no way to put this on my ipod as inteded... any ideas? the files are HUGE and there is no way to put them on a CD its 48 hours worth of book...

i know no way to roll back version of media player in vista or i would do that for the fair use program.

any help is great, thanks in advance