Once you have a published site, you can make changes to your Galleries and Pages and then apply those changes to your live site by clicking "Update Live Site" on your Remote.
To make changes to your Pages after you have published your work, just hover over the cover image, and look for the pencil icon. If you click on it, a drop down with four options will fall.
You will have the options to customize your gallery layout options, edit your cover image, edit the information for your page or edit the content.
From the option “Edit Project Content”, you can make changes to your Page via the Page editor and then when you are ready, you can click "Save Page.” When you click back to your homepage, you can hit "Update Live Site" at the bottom of the page and your changes will push to your live site.