【For Windows user】

(1)Right-click WINWORD.EXE and select "Run as Administrator" to open Word 2013/2016 with Administrative rights.
(2)Go to the File Menu and choose "Options."
(3)Select "Add-Ins" from the list at the left.
(4)At the bottom of the Add-Ins page, there is a "Manage:" dropdown list. Leave this on "COM Add-ins" and select Go.
(5)On the COM Add-Ins page, Choose the "Add..." button.
(6)Once you have Selected the "EndNote CWYW.dll" file, choose OK and OK again to close the COM Add-Ins screen. 
The EndNote tools should now be in Word.

【For Mac user】

(1) Open Word 2016. 
(2) In Word, click on the Word menu and select About Word. Make sure this reads at least version 15.25. If you do not have this version click on the Help menu and select Check for Updates. 
(3) Close Word, c
(4) Click the "EndNote" menu and select "Customizer" in EndNote program. 
(5) Check the box in front of the "Cite While You Write" option. Click next until the Customizer is finished.
If your version of Word is 16.xx instead of 15.xx, you are running the Mac Office Insider version of Word.