So, the first thing is to get Present3D installed on your computer.
This isn't difficult, but currently not as easy as installing a normal application, however, that will change for OSX users very shortly, as a new Present3D app will soon be available for download and soon after that, we will be adding a Windows app also.
But until then, OSX 10.8.x users can follow the instructions below, to get and build Present3D from source. For earlier versions of OSX, the instructions at the Digital Learning Foundation could be appropriate.
Before you download P3D you should make sure you already have the following :