1. Extract advPainter_1.5.1.mzp
2. Start Max. MaxScript>Run Script ... and choose the extraced file. A dialog box will inform you that installation is successful.
3. Install Advanced Painter action item (found under 'Painter' category) to your toolbar, main menú bar, or quadmenú. You set up a shortcut key or menú item for Advanced Painter the same way you would configure a regular 3ds interface item. Go to Customize / Customize User Interface, change the category to 'Painter' and assign a shortcut. Clik ok. Voila
. If you are having difficulty installing Advanced Painter or any other script, try checking out the script installation page, especially the videos demonstrating the process.