Resolved font awesome icons in the main menu

You can use icon on menu by using css before or after property.

Thanks for the answer.
But please tell me what and where I have to write.
Where could I find the before and after property, where do I have to write it? (in template.css or where?)
I'm sorry that I didn't understand your answer but I am not an expert.
I am using Helix-II as a template, I would like to set up font awesome icons in the main menu in this template.

If you send me your access then i'm gonna do it for you.
Waiting for your reply.

Please give me some time because now I only have Helix on my computer in XAMP.
I have to upload it to an online host.

Thank you Sohan for your time and your help, I will try what you suggest me.

I'm waiting for your reply.
Thanks.

Hi, check we have new guide how to add FA icons into menu: http://www.joomshaper.com/documentation/helix/adding-font-awesome-icons-into-menu

If this (edit every menu and the css file) is the only solution instead the method of writing [icon name='myname' /] in the menu title, this is a very frustration

If you want to use individual icon for each menu then you have to follow the provided solution. Or if you want to use same icon for every menu item the select the class and use css3 after property. Hope it will help. If this is harder to you then send me your access via pm. I will do it for you.
Thanks.