First let's identify which side of the tool performs which functions.

One side of the tool is used for stripping wires. You can tell because it has two blades, one on each side, as indicated in the first photo.

The other side is used for cutting wires. You can tell because one side is bladed while the other is flat, as seen in the second photo.

If you are using a slightly different tool, the use of it will still be very similar to how it is shown in this guide.