1. Download free software called Inkscape, found at inkscape.org.
2. In Inkscape, press File, Open, and select the SVG file from the extracted zip folder you purchased.
3. Right click on the image, and press Ungroup. You may need to ungroup multiple times to get to the bottom layer, depending on how many there are.
4. Click on the color you'd like to change, and then select a new color from the bottom panel.
5. Once complete, you can either print directly from Inkscape, or press File, Export as Bitmap to save as a PNG to use later.