Would like help to create horizontal submenu

Hello and firstly thank you for a great template which is much appreciated. I have studied the CSS and am applying changes to a child theme in local WAMP environment and all is going well.

I need to make the sub menu (dropdown menu) horizontal rather than vertical with a circular separator between menu items, tried using display:inline; and other css but cannot make it change.

Any help would be appreciated to achieve it.
Thanks in advance
Nel