Hi Chris, heard some bad stories about DIY kits bought to fix 'red ring of death'.
But my son has had 2 fixed free of charge, both consoles out of warranty.
< ' On July 5, 2007, the Vice-President of Microsoft's Interactive Entertainment Business division published an open letter recognizing the console's problems, as well as announcing a three-year warranty extension for every Xbox 360 console that experiences the "general hardware failure" indicated by three flashing red LEDs on the console '>
Sorry can't remember which site I went on to arrange a pickup and repair, but did it all online, took about 10 days to get console back, but invariably it isn't the one you sent them, that's why you have to remove your hard drive.
Just found this link in 'my favourites',
http://support.xbox.com/en-gb/pages/contact-us.aspx Hope this helps.......