Bittrex actually performed the swap for most of us.  Several pages back when the swap to the new blockchain was announced, the dev encouraged everyone to transfer their balance to Bittrex.  When the new wallet was released, Bittrex actually handled converting everyone's coins to the new blockchain, so whatever balance you had at Bittrex automatically changd over to the new coin.

But there was only a couple days notice of this, so for everyone else, he said to PM and he would provide instructions on how to verify your balance and transfer coins to your new MMXIV address.