The best and easiest way to do it is the same: with a handheld degausser, such as this one:
http://www.frys.com/product/487898?site=sr:SEARCH:MAIN_RSLT_PG
There are other ways of doing it, with varying results, such as running a corded drill over the screen (while it's running), or even a soldering iron. I've never had any luck with those methods ever helping much, though...