I'm sorry, sometimes i'm a bit too assumptious about general maya knowledge and that EVERYONE would already know about this...
Installing scripts
The zip archives can contain several types of files:
MEL (Maya embedded language) files contain the code that creates user interfaces and defines functions.
XPM files are icons you may use for your shelves (32*32 pixel) or images that appear within the user interface as a button or illustration.
MLL files are Maya plug-ins, that add new commands, nodes and so on.
TXT files contain additional information.
To install a script download the zip archive and decrunch it.
Copy all MEL files to your scripts folder (e.g. c:winntprofilesusermayascripts).
Copy all XPM files to the icon folder (e.g. c:winntprofilesusermaya3.0prefsicons).
Copy all MLL files to the plug-ins folder (e.g. c:awmaya3.0binplug-ins).
Plug-ins must be loaded in Maya (Windows -> Settings/Preferences -> Plug-In Manager). If you enable the "auto load" checkbox, the plug-in will be loaded automatically each time you start Maya.
To add the script to your shelf open the script editor and type the script name (e.g. connectPolyShape). Note that MEL commands are spelled case sensitive. In contrast to NT, Irix has a case sensitive file system, so you must also make sure the files are spelled properly. Next mark the name of the MEL script and drag it with the middle mouse button to your shelf. A gray MEL icon will appear. To change the icon open the shelf editor 'Options -> Customize UI -> Shelves', choose the 'Shelf Contents' tab and select the shelf item you just added, in this example 'connectPolyShape'. Click on the 'Change Image' button and browse to the folder where you copied the XPM file(s). Select the 'connectPolyShape.xpm' icon. ***
With lots of gratitude from http//dirk-bialluch.mayaring.com
