User Interface Overview
Imposition Wizard for Acrobat is a plugin, so you need to run Adobe Acrobat first. Then you will find Imposition Wizard in the Imposition menu of the Acrobat.
Load the document you want to impose, then click Imposition → Impose... to launch the plugin. You will see the main window like this (mac version looks the same):
Click the Generate button when your layout is ready.