You can buy the surround material and glue yourself, as this isn't a difficult job. But I would prefer to send them to David and let him do it. Shipping won't cost much if you're in the USA, and you'll know the job has been done right.

This will mean that you'll be without the use of your speakers for a while, but you'll have 'em back in about a week. Just remove the woofers, pack them carefully and send them to Speakerworks. They're inexpensive and they do good work.