Verify you have all the components shown here, and prep your solder station and tools.

There are two PMOS transistors that are slimmer, and two NMOS transistors that are thicker. Take special care to identify that your resistors are correct as shown, so that you know where to place them on the board.

Insert the transistors into the labeled slots near the center of the board. The orientation is critical, so be sure to line up the curved edge with the curved markings on the board, as shown.

Flip the board to the underside and solder the transistors. You can bend the long legs of the transistors to ensure they remain in place while upside down. Repeat this process for the remaining components.

Use wire cutters to trim down to the solder joint. Repeat this process for the remaining components.

When installing the 3 LEDs, the short leg must go into the white marking as shown. The orientation is critical.

Install the button switches on the left side of the board near the LEDs. The legs should only fit one way, and the orientation doesn't matter.

Pre-bend the x3 1k resistors. This will make them easier to insert when soldering.

Insert the three 1k resistors on the board as labeled, and as shown here. Flip the board and solder them.

The switch should be oriented to face outward as shown. When installing, be careful to use as little heat as possible since the switch can melt somewhat easily.

Flip the board to the underside and install the battery connector in this orientation as shown. Be careful not to install it backwards!

Plug in a 9-volt battery to the other end of the connector, and you're done! Thank you for building!