I get this question a lot since I deliver brushes as an option with logo design.
If you are on a mac you can simply double click the brush icon and it will automatically load in Photoshop.
Your brush icon will look like this:
If you are on a PC I don’t *think* you can simply double click. So to load it through PS here are the steps you take:
1. Open Photoshop and click on your brush tool in the tools palette
2. Click on the brush drop down at the top, then the little arrow on the top right, then select “Load Brushes”
3. Browse to find the brush file, click on it and select Load. Once the window closes you should see the brush in your brush box to the left.