ETH Pending for >11hrs

We have sent ETH transactions from our exchnage and they appear on the blockchain but are stuck for over 11hrs in pending

subsequent ETH requests are pending because this first one is not processed

https://etherscan.io/tx/0x311ecd5f068b8f6b0c89ad23bd29bc5373f941b087da38211c4cf4c6de0977a3

How can we increase gas to push this through or some other suggestion?