Uninstalling LightRigger from 3ds max 9 and higher:

To uninstall LightRigger, delete the following files and folders (along with their contents):

Settings:
Map Path: (Customize menu > Configure Paths/User Paths > Bitmaps/External Files tab > select "3dsmax\Maps\LightRigger\" in list > Delete)
UI Button: (Right-click on the "Open LightRigger" button > Delete Button)
Additional Help: (With 3ds max closed, open the "Program Files\Autodesk\3ds Max\plugin.ini" file and delete the following line:
"LightRigger Help System=C:\Program Files\Autodesk\3ds Max\help\LightRigger\LightRigger.chm".  Also open the "Documents and Settings\username\Local Settings\Application Data\Autodesk\3dsmax\32bit\enu\plugin.ini" file and make sure that any such entries are deleted.)

Files:
Documents and Settings\username\Local Settings\Application Data\Autodesk\3dsmax\32bit\enu\ui\usericons\LightRigger_16a.bmp
Documents and Settings\username\Local Settings\Application Data\Autodesk\3dsmax\32bit\enu\ui\usericons\LightRigger_16i.bmp
Documents and Settings\username\Local Settings\Application Data\Autodesk\3dsmax\32bit\enu\ui\usericons\LightRigger_24a.bmp
Documents and Settings\username\Local Settings\Application Data\Autodesk\3dsmax\32bit\enu\ui\usericons\LightRigger_24i.bmp
Documents and Settings\username\Local Settings\Application Data\Autodesk\3dsmax\32bit\enu\ui\usermacros\LightRigger-OpenLightRigger.mcr

Folders:
3ds Max\Help\LightRigger\
3ds Max\Maps\LightRigger\
My Documents\3ds Max\MaterialLibraries\LightRigger\
My Documents\3ds Max\Scenes\LightRigger\
Documents and Settings\username\Local Settings\Application Data\Autodesk\3dsmax\32bit\enu\Scripts\LightRigger\