Take your pick, mate... http://www.google.co.uk/search?hl=en&q=dvd+multi+region+hacks&meta= It's not always possible though - not all models are capable. Others, however, can be converted by entering a code on your handset. Failing that, try your PC - you can usually change a DVD drive's region through Device Manager (you can only do it four times, though)...
Try this Said it works for GX300 as well http://www.dvd.reviewer.co.uk/info/multiregion/full/Sony500.asp