How to add drop down menu in Blogger

http://www.engindev.blogspot.co.uk/2013/11/how-to-create-drop-down-menu-in-blogger.html

http://www.bloggingtuition.org/2013/08/css3-drop-down-menu-for-blogger.html

https://www.youtube.com/watch?v=fkC7D0K4f6U