*NOTE* hot plastic isn’t fun and can burn you pretty bad! Use caution when melting the cord ends!!
You will notice in this picture that the turquoise set of cords are melted and the blue cords are cut and ready to be melted. Take your lighter and place the flame as close as you can to the cut cords. You really need them to get nice and melty. When the cord ends turn brown and get bubbly, take the flat side of your scissors and press the hot cord onto the collar. You might have to have another pass with the lighter if the cords haven’t fused properly. When both ends are melted, they’ll look like the second picture