Changing the header for Aperio Prototype

Hello,

I’m brand new to wordpress and coding but for the most part I understand and I’m capable of simple editing.

Currently I’m using the Aperio Prototype theme seen here. If you notice at the top left hand corner is the image displaying the name of blog or template rather. I would really love to change this to say my blogs name. I’ve already created a png web ready image in Photoshop but I’m at a lost as to how I would go about making this change. If there is anyone around willing to help I would very grateful.

Thanks everyone.