1.

Navigate to Edit> Material Editor. 

2.

Select the surface you are wanting to change. In this instance we are selecting the window.


3.

Click in the box Colour Map>Browse to begin locating your image. The image must be in .JPG format to be read correctly.

Simply hit Yes and away you go.

NOTE. 

Ensure you change the Type to Outside View when changing the images of windows to ensure the image is rendered correctly.