I am very sorry to state that as of January 11, 2013, this achievement is unobtainable due to EA closing the servers for this game. Full details for the closure are provided in the link below.
2013 Electronic Arts Online Service Shutdowns***ORIGINAL GUIDE***
Simply pause the game at any time and go to the instant replay mode. Then choose a starting marker and a closing marker using the X button. Your replay doesn't have to anything fancy, it can even be a simple as you dribbing the ball. Once you have your markers set you are given the option to save using the B button and once you choose to you are then given the option to Upload to EA Sports World, highlight and select it. It will then encode your replay and once its finished you will then select a slot to save it, give it a name, upload it and presto!
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I wish it was still as easy as this now, but sadly not anymore....and this is why I now boycott EA Sports games.