EndNote allows you to select and change the citation style of references in a document. The EndNote toolbar displays the current style, and the drop down arrow will reveal other popular or recently used styles. The Select Another Style option opens a pop-up with the hundreds of citation styles that come with EndNote.

Changing the citation style in Word will automatically refomat all the citations and the bibliography according to the new style's rules. 

Sometimes, you may need to edit an existing citation style to customize it for your exact needs. This could be as simple as adding page numbers to an in-text citation or using a full journal name as opposed to an abbreivated title. The below links and documents illustrate downloading, editing, and creating new output styles.

EndNote's Cite While You Write (CWYW) plugin for MS Word is part of the desktop program installation. If you're using EndNote Web, you can download the plugin. This connects your EndNote references library with your word processor.

To use CWYW, have EndNote open while typing in Word. When you need to insert a citation, click the Go to EndNote button on the EndNote toolbar, which will bring up your EndNote window. Select the reference you want to cite, and then go back to Word click the Insert Citation button on the EndNote toolbar. This will insert an in-text citation at the insertion point and a reference listing at the end of the document, both formatted to the selected style.

You can edit a citation by right-clicking it and selecting Edit Citation from the pop-up menu. Use this if you want to exclude the author or year from a citation.