In fact, all you need is:
1. Your own milk and coffee, obviously. Both are available at any grocery store.
2. A microwaveable container with a lid. Make sure it's something you can shake.
3. A microwave (I understand that, due to the undying popularity of bullshit films like The China Syndrome, this part is a deal-breaker for some of you. To that I say, "Your loss, hippie.")
The rest of us stopped trusting Michael Douglas in the '80s.
Once you've gathered all that up, do this:
1. Pour your coffee and add your chosen sweeteners and enhancers (I mean booze). You want to have this ready before you deal with the milk.
2. Pour the milk into the container. As the last sentence clearly shows, I'm not an "exact measurements" kind of guy. I can tell you that you need to leave enough room in the container for the milk to double in size, preferably with a little additional room left at the top.
So like this, I guess.
3. With the lid firmly in place (don't get cocky, double check), shake the milk vigorously for at least 30 seconds. As you might have gleaned from the previous step, when you're done, it should look like you have twice as much milk.
Use your maths!