i think i saw a how-to somewhere on this forum. let me see if i can find it.
*edit* cannot find the forum but i remember you have to remove the headliner and there are bolts. but after you remove them there will be a groove down the sides where the racks used to be. mazda sells fillers but from what ive read they arent cheap. if you looking to just remove the crossbars check this HOW-TO http://www.msprotege.com/forum/showthread.php?t=22943&highlight=roof+racks.
