If the page sections are editable on the site, you can make the changes by following these steps :
1) Go to your site page
2) Click on Enable Editing button in the top right to display all the editable areas.
3) Click on the editable area to display the WYSIWYG editor.
4) Make the changes and click Save Changes button in the top right.
If the page is not editable on the site, please contact firstname.lastname@example.org with the page name and content to be updated.