To access your EthereumWallet's plain-text private key, you'll need to have Chrome, and enable its Developer Mode (see Chrome's Settings to do that).
1. Open your EthereumWallet in Chrome
2. Right click anywhere and select Inspect...
3. In the Developer window, select Console
4. In the Console, type or paste in "wallet._private.toString('hex')" without the quotation marks and hit Enter
This will produce the private key to export the wallet to the service of your choice.
Disclaimer: Please make sure you do not share your private keys with anyone, including Jaxx support team, as if someone gains access to them, they will also be able to manage your funds.