I am a novice when it comes to electrical wiring. I purchased a IPP-15-LW leviton motion sensor switch to replace a current switch in my garage. The switch is one of two switches that are in the garage controlling the same group of lights (I think this is called a 3-way switch?) and it can be turned off or on from either switch. When trying to follow the directions on the instruction sheet, the instructions leave several steps out from what I can see and I can not get the motion sensor working. I do not need the second switch at all after the replacement of the motion sensor, so it could just be eliminated. Would someone be so kind as to point me to any document that would step out the installation instructions step by step? Thank you!

Try this:
IPP15-1LW > Wall Switch > Occupancy Sensors > Energy Management > Lighting Controls (Box Mounted) > Product Catalog from Leviton Electrical and Electronic Products

Then select instructions, drawing or whatever. Good luck