1st. Open PS and select the brush tool. Next hit the little arrow and bring the pull down list up. Now there is a arrow to the right , clicking it will bring up a list of options , select Load Brushes. Simply select the file that way or....
then load Photoshop.. click on the brush tool.. then load the brush in from the list you see, there is like a little button u gotta click on to pull up the list of brushes.