Some products are in .abr format (Adobe Brush) and need to be imported into CS (Photoshop). This article shows how to do this.
The recommended install path for this product on the PC is:
C:\Program Files\Adobe\Adobe Photoshop CS3\Presets\Brushes
On the Mac:
Applications\Adobe\Adobe Photoshop CS3\Presets\Brushes
Once you have the product installed, you will need to add the brushes into the brush palette in Photoshop.
Select the brush tool.
Go to WINDOWS –> Brushes
In the upper right corner of the palette, click the button to see more options in a new menu. On the bottom of the menu, you will see the entry for Rons presets. Click on the entry.
You will have the option to replace or append. Choose append to save your existing brush presets and add the new brush presets at the bottom.
Now click on a brush preset to use in your Photoshop creation.