Acquired Ether in the presale. Using Mist, transferred ETH into an account. How do I split into ETH and ETC? Want to take the ETC to an exchange. Thx.
this might be what you are looking for:
Assuming Mist doesn't deal with EIP155 which makes your transactions appear on only one of the Ethereum blockchain or the Ethereum Classic blockchain (depending on which you choose), and assuming you do now have ETC (you can check your balance using a blockchain explorer for ETH and ETC) you have at least two options:
Import or send your funds to a wallet that supports EIP155 such as recent versions of geth and Parity, ensuring that you use the same address on both chains. Importing avoids an extra fee for gas (transaction price). Then load your EIP155-supporting wallet and send your ETC to an exchange.
Use the splitter contract to send your ether to two different addresses -- one on the ETH chain and one on the ETC chain. You can probably list the exchange deposit address as the recipient of the ETC transfer without issue to avoid paying for even more gas.
In all cases, you should send a small amount of ether as a test and ensure that the transaction only appears on the chain you expect. That being said, the more reputable exchanges might be able to help you if you ended up sending a transaction on both chains to the same address, but I wouldn't count on it.