One place for speaker repair is http://www.speakerworks.net/
$30 for one speaker, $55 for two, $98 for four..
They also offer Do-It-Yourself kits if your handy...
Another place that will do it or sell you DIY kit is:
http://www.speakerrepair.com/
Call a local audio store near you. They may know of a place near you. Then you could just drop them off.
I personally like re-foaming the originals. Unless you're lucky to get the exact same original woofers, etc, a new driver could change the sound of your speakers.
DIY kits also at:
http://www.speakercity.com/refoam.shtml
http://www.speakerbits.com/net/catalogs/cat9.aspx