Pop in both LEDs and align the wires. Bend the LEDs into the channels on the back of the card. Make sure to bend close to the card to insure the ink sticks to both the wires and has good adhesion to the plastic.

Carefully squeeze the pen to apply a generous amount of ink. Draw a thick line from one battery hole to the LED and then connect both LEDs together.

Don't worry if you get some on your hand or on some spots around the card, it washes right off with water!

Apply a good amount to the inside of the holes and on to the front of where the batteries will sit.

You can use a drop of ink to hold the batteries or a piece of Copper Foil Tape.

Snap the pins into the heart. Place the two nub-less gears into the top pins. The pressure applied to the bottom gear will push the copper foil tape underneath and bridge the connection between the batteries.

Apply a strip of Copper Foil Tape on the back of the heart, underneath the top two pins.

To keep the LEDs lit, you can bridge the connection by simply applying tape the top of the batteries.

Snap in the assembled heart just in time to lighten up your valentine's geeky heart!