When logged into your wallet, at the top you'll see a button that allows you to switch between your ZTX and ETH wallets:
Click anywhere in this area and you can toggle between currencies.
Below the currency toggle, you'll see your balance in red, as well as your wallet address and your wallet's approximate value in USD in white:
Beneath this area, you'll see the send field, which let's you send tokens out of your account:
In the 'To' field, enter the wallet address or email of the recipient (note that sending to an email address is only available for recipients who have already signed up for Zulu with that specific email address). If sending to a wallet address, make sure to check each letter of the address to avoid sending funds to the wrong wallet.
In the 'Amount' field, enter the amount of ETH you would like to send. Since ETH is divisible to 18 decimal places, even seemingly small errors in how you enter the amount can have a big effect on the value you are sending. For this reason, be very careful to check that you've correctly entered the decimal places for the amount you would like to send.
Once you've double checked the recipient's wallet or email address and the amount, click the SEND button. At this point, confirmation dialog will appear, prompting you to enter your password and hit the confirm button before sending is initiated.
Transactions can take several minutes to be successfully validated on the blockchain. During this process, the transaction will be marked as 'Pending'. You can view the status and details of your transaction (via Etherscan) by clicking on the sender's address, followed by "View on Etherscan":
Once the transaction is confirmed (marked 'Success' on Etherscan), that's it, you've successfully sent ETH from your Zulu Wallet!