Convert a static menu to dynamic

We are working on this site https://locusathens.com and we need to make those menus to be able to open and close when someone clicks on them. Does anybody know how to do this with coding or a plugin ?

I have searched a lot but cannot find a solution.
Someone said that it is possible with the use of java script but I am not really familiar with it.

Any help would be greatly appreciated.
Thanks in advance.