How to claim Bitcoin Cash from Block.io Initially Block.io stated they would support Bitcoin Cash in September and that never happened.  :(  After reaching out to them they stated:

"The Bitcoin Cash network seems to be dying in favor of the new Segwit2x fork its proponents want to push. While we continue to index the Bitcoin Cash blockchain, we do not believe full support for this network is merited given its low adoption.
If you wish to use your addresses to claim your Bitcoin Cash equivalent in the mean, see block.io/dashboard/settings -> Access Private Keys, and then claim your Bitcoin Cash from a service that supports that network."

At this point I attempted to transfer Bitcoin Cash to Btc.com with their tool but it is stating that no funds were located so they probably are not compatible with Block.io.   

Does anyone have a service that will support the transfer of Bitcoin Cash from Block.io with my private keys so I can get it off their exchange and into my wallet?  Any thoughts or assistance is appreciated!
It's possible! But it's complicated :]
The main reason is block.io are using multisig addresses, meaning that it's not the usual address that you can redeem funds with only one private key, but here we require two private keys to sign every transaction. 

EDIT - This solution used to work for some time, but it doesn't work at the moment

It seems that blockdozer.com changed their API and their AJAX/CORS policy in some way that makes it impossible to query outputs and to submit transactions. I was able to overcome their AJAX by disabling security on the browser, however the raw transaction that's being generated contains special characters such as "|" and the API doesn't support that. It did work about a month ago though, but not any more

Since Ik'm no expert on this I submitted a comment to the developer that implemented bitcoin cash support in Coinb.in, I'll update here once I get a response. Here's the PR and comment in Github:

https://github.com/OutCast3k/coinbin/pull/113

Phase one - Acquire your private keys

First phase is to your private keys from Block.io - Log into your wallet, go to "Settings", then press "Private Key Access". You'll get an email with instructions how to proceed. At the end of this process you should have a file that contains something like this :

* Address: 3ET4FuXvHahN4WwrJ3dyCLsoVbDVZtVEUU
* Address Type: P2SH
* Required Signatures: 2
* Redeem Script: ....
* Redeem HEX: 5221039960aa771270362b7e49400433e103c59e12c6a43a946d4b048f7efcc68bc0bf21028825d729387c6b0aafae1c47802c62d7f965de1800d6122143c681044c50700452ae     
* Public Keys: ["039960aa771270362b7e49400433e103c59e12c6a43a946d4b048f7efcc68bc0bf","028825d729387c6b0aafae1c47802c62d7f965de1800d6122143c681044c507004"]
* Private Keys: ["KyubGochD3MkXW4KkT95K6FXbZSrtHg6creF6xaRDc9C3qkyidza","KxFLJ2n76i2W9WB2YdJd1zCL2Kmgpk1vfB2XEynSpQWsYCe4bfqn"]


Phase two - coinb.in

I tried to do it the easy way using Electron Cash - there's an option there to import multi sig addresses but it doesn't work. I had to sign the transaction manually and broadcast it to the BCH main network. coinb.in is an awesome tool to do that, however at the moment the pull request for using BCH isn't merged yet, I deployed a version of the tool here :

http://galed.codus.net/coinbin/

Alternatively, If you want to be extra cautious you can run the tool on your local machine by running these commands :

git clone https://github.com/dabura667/coinbin.git
cd coinbin
git checkout bitcoincash
open index.html


Phase three - signing a transaction and braodcasting

PLEASE PLEASE PLEASE WATCH THE INSTRUCTIONS in this youtube video to get a better sense of what needs to happen: https://www.youtube.com/watch?v=oUSVmLegj8k - If you're dealing with large sums of BCH you could end up losing everything, so please be careful! 

The one difference is that you need to be careful to choose the bitcoin cash network, otherwise you'll be broadcasting transactions on the BTC network:


Click New -> Transaction 
Enter the redeem HEX that you received from block.io in the first box (Address, WIF key or Redeem Script)
Click on "Advanced options" and change the network to "Bitcoin Cash mainnet"
Put in the amount you want to transfer and the address, make sure that the fee is not too high
Click submit, you will get a long HEX string. copy it
Go to "Sign" , paste the string, paste the first private key from the file that block.io sent you, click "Submit", Copy the string
Paste the string into the second box, copy paste the second private key from the block.io file, click Submit, copy the output
Go to "Broadcast", paste the string and submit.