Edit your file with CS3 and publish the swf like you normally do
Grab this hex editor from here - http://www.chmaas.handshake.de/delphi/freeware/xvi32/xvi32.htm#download
Open the swf with it
Find the forth byte which should be 09 ( flash player 9 ) and write there 0A ( flash player 10)

That's all, the first time it's the harders after that, it should take 5 seconds max