Once you have finished editing, click on the 'Sign Off' button, found on the bottom right-hand side of the page. This will then take you back to your Round Overview with your round signed off.
You can also now save your progress as you go by pressing the 'Save & Exit' button. If you don't have time to finish editing the round then simply save your progress and finish it later.
You will always need to press the 'Sign Off' button though to finish the process.