How to install Brushes in Adobe Photoshop CS5?

1. Locate the brushes folder inside your Photoshop installed directory once your inside the folder drag and drop your brushes there.

2. Open photoshop, open brushes, go to load brushes and choose your newly installed brushes

In the Brush pallet, At the top right click until a drop menu appears.
The just select "Load Brushes..." Also if you click twice on your brush file, it should automatically load in Photoshop.