To edit a page just click the Edit entire page link on the bottom-right of each page (inside the yellow area). This will present the enitre content of the page in an editable text area. Note that each comment that was added to the page appears inside curly braces – when you edit the page make sure you do not accidentally delete these braces, otherwise the page will look strange.
Beneath the text area, to the right, you can check Show versions to see which previous versions of the page were saved. If you select one of these versions, you will get its text inside the text area for editing. You can see previous versions even for a deleted page, so you are able to recover its content or parts of it.
When you edit a page you are responsible not only for your own words, but also for all other people that contributed to that page. Even if it looks easy to change, delete, or improve the text, please remember that there is a person behind these words, a person that you cannot change or improve. For this person, the way you treat his or her words is the way you treat him or her, and it may affect the way this person treats you. So when you edit, try to treat what others said with respect, sensitivity, and empathy: