First make sure you have removed any duplicates from your library, before you begin to cite references in your Word document. This is important to avoid any errors in your bibliography.
Position the cursor on the citation you wish to edit, and click to select it. The Cite add-in window will appear, with the citation(s) you wish to edit displayed.
To delete the citation from your Word document, click on the 'X' to the right of the 'reference pill', and then click on Save changes.
To edit the citation, click on the 'reference pill' (not on the 'X' to the right of it) and this will open the edit reference panel.