I want to move my BTC wallet from Block.io to Blockchain.info.
As transaction fees are $10 on block.io, I would like to do this by exporting my private key and importing it on the other side.
How can I view my private key on Block.io?
Log in, click Settings -> Private Key access -> Access private keys. You will recieve e-mail confirmation with link to private key access.
Then you will have to transfer your funds to another wallet. This is how I've claimed my BCH. The same will be for BTC but you shouldn't change Network and should set larger fee.
First of all you should get from security settings of you block.io profile: "Redeem Script Hex", and two private keys. (actually you will have some more strings and values but only these three required to claim your BCH).
I know this seems strange and may cause doubts and believe me I wasn't sure too. But the real deal was: getting BCH (I had 0,5 of BTC at block.io wallet) or getting nothing.
That's it. You will recieve TXid which you will be able to check at https://bitcoincash.blockexplorer.com
Actually all regards should go to ohad serfaty but I can't comment the post where he advised this method because of low reputation.