Unscrew the two tiny screws on the terminal block as shown in the picture. Since we're making space for wire, the screws shouldn't come out completely.
Insert the stripped end of the red wire into the hole on the terminal block with the (+) symbol.
Insert the stripped end of the black wire into the hole on the terminal block with the (-) symbol.
Tighten the screws to hold the wires in place. Give them a little tug to ensure both wires are secure.