How to install photoshop brushes
After you have downloaded the zip file, unzip it and save the .abr file on your hard drive. You can save this file anywhere you like but for ease of use you should consider saving all your brushes to your Photoshop installation folders.C:\Program Files\Adobe\Photoshop X\Presets\Brushes on Windows OS (where X is the version number for your version of Photoshop)
Open up photoshop and activate the brush tool (B)
From the brush palette click on the small down arrow to open the brush preset picker.
Click the small arrow at the top right hand corner and select the load brushes... from the menu list.
Navigate to the brush set you want to load, click Load and you're done.
Select the brush from the brush preset picker begin using it.