Font awesome on posts

I would like to change the font awesome icon in the post format (currently pencil) on the home page http://colourdiamondexpert.com.
How do I do that with css?
thank you

Hello Robert,

I don’t see it on your home page, can you please provide some explanatory screenshots?

You can upload screenshots to your WordPress Media Library and share a link, or you can use one of the online screenshot services.

Kind Regards, Roman.