With your wire's properly tucked. and managed, it's time to connect both sides of the ESC's enclosure.

Lift the bottom case (side with PCB) by the corners and lower the case evenly on all corners.

Make sure the enclosure tab's are aligned and within the designated area. Keep an eye on maintaining the position of the rubber gaskets and switch.

Do not forcefully push down! There should be some resistance, but not enough to break anything or to cause difficulty.