You can return to the Responsible Gaming section by going to Menu > My Account > Play Responsibly > Deposit Limits to select a new amount or time period. You can find this here.
However, this does not take effect immediately in all situations. Once set, the confirmation page will let you know when the new Limit starts.
Please note that once it's time to accept a new limit, you must do that before depositing. If you do not accept the new one before depositing then the old limit will restart.