Make a .gif file -> save to desktop -> semi click the .gif -> apple+I -> click the image preview -> apple+c -> semi click the file you want to change -> apple+I -> click the image preview -> apple+v
You could turn on magnification of the icons on the Dock. Control-click on the divider bar on the Dock and select "Turn Magnification On." If you go into the preferences, you can adjust the amount of magnification given to the icons.
