I need help in Editing my footer (Attention: Kharis)

I used this Css code:

.site-info {
   display: none;

to remove the copyright info at the bottom of my Airi theme. Now I need to replace it with my own Copyright info and I don’t know how to go about it. Can you please help me? Thanks in anticipation for your prompt and useful response.

If you need to see the site: www.digmarto.com

Hello, please check this link:

Please feel free to ask any other questions that you might have.

Kind Regards, Roman.
aThemes Support