Suite of tools that help to ease the manipulation of positions and selections of vertices
Maybe after downloading the filename is 'Verty.mzp.zip' instead of 'Verty.mzp'. Just rename it correctly.
Start Max4 or a later version.
Select 'run maxscript' from MAXscript in your main menu bar. Choose 'Verty.mzp'.
You can find the script in the category 'Vertex Tools'.
When executing 'Verty.mzp' a install-script is executed automatically - allowing you to setup a menu hosted in the main menu bar - containing the script.
To do so: type in the text field 'scripts' and press the 'add' button. Now close the floating window. Choose 'Verty' from the menu 'scripts' from your main menu bar.