Ok this will require a lot of changes and if you are not comfortable with php and js you should fiind someone who knows this or just make a custom work request.
First you need to go to pin-management.php and edit the listing_pins functions . There you need to add the details you need in the infobox .
Then you need to edit the google_map_code.js ,google_map_code_prop and google_map_code_home.js files (in js/google_js). Here you need to alter the create marker function and add those details to the maker object.
In the same files look for the line where infobox content is added. Edit that and add the new info.
Css work may be also required.
Again , make sure you know what you are doing since this is a sensible area. Don;t forget to back up before editing anything.