To deposit/withdraw ETH select the deposit or withdraw option, shown next to the current amount of collateral. Example below.
Collateral position
In the new window enter the amount to deposit (if you selected deposit) or withdraw (if you selected withdraw). The overview in the window will show the new liquidation price. Example below.
Collateral adjust deposit ETH
When you have the amounts you like press the green deposit/withdraw button in the bottom right corner. Then agree with the payment using your web3 wallet, in this example metamask. Example below.
Collateral payment web3 wallet - deposit
Once the transaction is send wait for it to be included in the blockchain. If you refresh the page you will see your adjusted collateral position. Example below.
