Editing the web pages is a straightforward process using the WYSIWYG editing tools provided by Sitebuilder - except for the map, which uses some special code. Each page has a map added already. To get the map to show the required geographical location you need to provide it with coordinates in the right format, and then click "Update". The https://pleiades.stoa.org website provides the coordinates in the correct format, and includes a way to easily copy them into your clipboard.
On a Pleiades page for a location, simply click on the button to copy the coordinates, then go to your page and paste it into the coordinates field on the right. Click update.
Copy the coords:
Paste and update: