If you add more citations to your paper after the formatting process, you can update the citations and the bibliography by selecting the Format Bibliography command again. Word: Click Update Citations and Bibliography or click the corner arrow to bring up the Configure Bibliography dialog.
Note: You do not need to unformat your citations in order to reformat them.
To reformat your paper in a different style:
Go to the Tools menu, then the EndNote submenu, and select Configure Bibliography again. From Word, you can select a new Style in the Bibliography group or click the corner arrow to bring up the Configure Bibliography dialog.
Select a new style from the Format Bibliography tab and click OK.
Your citations and bibliography are updated for the new bibliographic style. See Adding Styles to the Output Styles Menu for information about expanding the list of available styles.