How to Use Negative Energy to Expand Space

We don't know how to build this thing, but the universe's list of rules don't explicitly prohibit it. But what is the recipe? What does it actually say? He's saying it needs negative energy or negative mass. And then what do I do with that? Do I just put it in front of me? Do I need to lay it out between here and Jupiter?Do I need to spit it out in front of myself? So far, every solution requires using some kind of negative energy density matter behind you in order to expand space.