1. Click the brush icon in your tool bar section.

2. Up the top under File Edit ect. you will see Brush: click the little down arrow.

3. Now click the little arrow > and then go down to load brushes.

4. Now you will get a Load box up , go to where u saved your brush/s and click on the brush you want then click Load or you can just double click on the brush.
This is how u upload brushes into ps it works with brush packs or just 1 brush.
You can Also unzip your Brush files to your photoshop brush directory
C: program files/photoshop/presets/brushes
Hope it helps