I have a question on adding an image to header

It depends where the image is and how it’s being inserted into the page. A link to the page in question and some indication of which image you want to replace would probably help.

I’m using a wordpress theme called gears. I have a field glass below the main header I would like to replace with a picture I have. my site can be found at wkhoopes.com if you can take a look.

The relevant markup in the home page (I assume that would be index.php) is:

<div class="banner">
<div class="paddings">
<img alt="Gear" src="https://www.wkhoopes.com/wp-content/themes/gear/images/ico.big/bino.png"/>
<h2>Early to bed and early to rise!</h2>
<p>Makes a man healthy wealthy and wise</p>
</div>
<div class="clear"/>
</div>

So the current image is called bino.png, it’s 128 px x 128px and is located in the wp-content/themes/gear/images/ico.big folder.