You solder one capacitor to the plus (+) motor terminal and the other end of the capacitor to the metal motor case (shell). You solder another capacitor to the minus (-) motor terminal and the other end of it to the motor case (shell). The third capacitor is soldered between the plus and minus terminals.
Did you understand what I meant? I don't know if my explanation is clear enough. When you can't use your hands to describe something it doesn't seem right.
You may not have +/- markings on the motor, don't know. Just solder one capacitor to each of the motor terminals and then to the motor casing and one across the motor terminals. Maybe that explanation is better. None of the capacitors are in series. Some people don't use the third capacitor between the terminals but you've got it, put in on.
I think I just repeated myself. I thought I could find a drawing somewhere quick while I was writing this but to no avail.
Go to:
www.ezonemag.com/pages/efaq.htm
This is Frequently asked questions about electric flight and under the section "motor" one of the topics has a short paragraph on the purpose of the capacitors and how to solder them on but it does not have a drawing either. Sorry bout that.
Good Luck