Download the mzFishTool_b01.zip file and extract the files.
Place mzFishTool.py in your Maya scripts folder.
(Usually found in the following folders.)
Open the Maya Script Editor. ( Windows > General Editors > Script Editor)
Click on a Python tab and type in the following lines of code:
import mzFishTool as mft
Then click on the play button
Follow the above instructions, but don't click on the play button.
In the Script Editor menus, select File > Save Script to Shelf…
To replace the shelf button image with the mzFishTool icon image:
Right mouse click on the shelf button and select edit.
Select the Shelves tab.
Where it says Icon Name, replace the current image with the mzFishToolIcon.png image.