EndNote comes with several of the most popular output styles (like APA, MLA, Chicago, and hundreds of discipline- and journal-specific styles) preinstalled but if you cannot find the citation style you need listed, then you can download one of over 6,000 styles from EndNote.com.
1 - Visit the link below
2 - Find and download the style you want to add from the results
3 - Open the style file
The file should open in EndNote, if not then:
a) Go to your Downloads folder
b) Find the file
c) Right-click the file
d) Choose Open with...
e) Select EndNote from the list
4 - In EndNote, go to File Menu and choose Save As. Remove the word “copy” (if shown) from your style’s name and click Save
5 - Click on File Menu and choose Close Style