Uninstalling LightRigger 3ds max 4.2 - 3ds max 8:

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 "3dsmax\plugin.ini" file and delete the following line:
                             "LightRigger Help System=...\3dsmax\help\LightRigger\LightRigger.chm".)

Files:
3dsmax\ui\Icons\LightRigger_16a.bmp
3dsmax\ui\Icons\LightRigger_16i.bmp
3dsmax\ui\Icons\LightRigger_24a.bmp
3dsmax\ui\Icons\LightRigger_24i.bmp
3dsmax\ui\Macroscripts\LightRigger-OpenLightRigger.mcr

Folders:
3dsmax\Help\LightRigger\
3dsmax\Maps\LightRigger\
3dsmax\Matlibs\LightRigger\
3dsmax\Scenes\LightRigger\
3dsmax\Scripts\LightRigger\