For recent versions of Photoshop, just double click the "GD_Tools.tpl" file.

If that doesn't work:
A. Open the Photoshop Tools Presets panel (Window -> Tool Presets).
B. Click on the triangle arrow at the top right of the Tool Presets panel to bring up the menu and select "Load Tool Presets...".
C. Select the "GD_Tools.tpl" file.

You'll find the brushes at the bottom of the Tool Presets panel when the brush tool is selected.