simply click on that item in the Grid, details will be displayed in the Simple Editor where you can edit most commonly edited fields.
To edit one or more items individually,
select one or more items that you wish to edit individually
Click on the dropdown button "Edit/Revise Options" and it will show various options you have to edit a Listing.
Click on the option "Edit"
Full Editor window will open where you can edit the selected listings one by one. When you select multiple listings, the Full editor window will display two additional buttons "Next" and "Previous" that let you navigate to next and previous respectively selected listing for editing.