If you have small gauge wire, or like in this case, soft flexible stuff.. it's not always easy to get the wires into the housings..
Using a small screw driver or hex keys , what ever you have handy.. line up the spoon into the housings, and push the tip down from the back, if you put the tip of your screw driver directly at the back of the tip, where it meets the insulation, you can easily click it into place