You need to make a copy of the icon picture with a texture editor program past it in a blank space in the texture file you want it in. Then locate the co-ordinates of your new icon picture and put an entry of it in the "MainViewIcon" brush file.
To locate the position of the picture on the canvas use the measure tool from the top left corner of the canvas. Check the accuracy by comparing your measurements with other pictures in the same row and column.
