The circuit is fairly straightforward and can be assembled well within an hour.
Headers (included with Trinket) may be soldered to facilitate attachment to a breadboard or proto board. Other parts may be pressed into the breadboard. Ready-made hookup wire or cut to fit wires make the connections.
The same circuit with Gemma. The LEDs share D0. D2/A1 is hooked to the junction of the photocell and a 1000 ohm (1K) resistor. If you wish to just rely on the power pack on/off switch, you can eliminate the photocell and 1K resistor.