Step 2: Gut the beast and evaluate what you can do with what you have.
Apparently, this shredder came in a version with an AC motor, and a version with a DC motor. I have my doubts about reversible AC motors... correct me if I'm wrong, but nonetheless... When taking out the motor, check for a sticker with the specs. In this case it's a 120V DC motor. Note that there are 4 wires coming out of the motor,and two of those are obviously the DC power wires since they are black and red. The other two are blue, and from what I can tell, they are probably from a sensor of sorts, since there was an overload LED on the cover.
The fact that this is a 120V motor can be considered a good thing, since no transformer will be needed in the new circuit. We now also know that we need a way to convert 120V AC to 120V DC.
Enter the magical world of rectifier bridges!
Note : the actual voltage from the outlets in your home may vary.
If you dig a bit deeper, you can find a micro switch that cuts power to the unit if the bin is removed. Leave it be. I won't talk about it either in the following steps. Just remember that it's part of the AC wiring.