Someone helped me with same question.
First I recommend you install a child theme, those instructions are at the site for Nisarg and also WordPress.
In Style.css change:
.navbar-brand{
font-size: 0px;
width:235px; /*width of your image*/
height:48px; /*height of your image*/
background-image:url(‘http://site-name/wp-content/uploads/… Imagefilename.ext ‘);
margin:5px; /* If you want no margin */
padding:0px; /*if your want to padding */
}
Of course you can add this code to the “customize CSS” but I have found child themes help me track my changes.
…Brian