Warning: SEPA has never been "quick"! At least not for me. But I still get my money after a few weeks. I never withdarawl more than 999 euros in one go.
You have to switch your account to EURO. It will cost you 2.5% of your dollar assets. Then you need a SEPA bank account. You verify it with Mt. Gox and than you can withdrawal your money.
It's maybe not worth worrying about. It might save you a few weeks. Bank transfers always take long for Bitcoin. There are always times where individual exchanges are faster, but once all this AML shit comes with in it takes forever. Plan just several weeks or month. A year ago there was not so much money on Gox. Therefore, it was faster, also because Gox has ignored the laws. Now while everyone wants to withdrawal and the FINCEN is behind them it takes maybe forever. I did not even know until a few weeks ago that USD withdrawals went so fast in the past. I always tought it would be normal to have to wait several weeks.
So nothing has changed for me.
Where do you get the information that you can convert money on gox for 2.5%? I don't believe this is true. You would have to buy for USD then sell for EUR, thus it'd be the difference between those plus the fees (two times).
see the bottom of this https://support.mtgox.com/entries/20800336-Multi-Currency-Trading