First of all start with the Power Board assembly, in the first step, you need 4 M2x5mm bolts (two for each side), 2 frames, and a Phillips screwdriver.

Assemble the frame to Power Board using the M2x5mm bolts and don't tighten the bolts all the way yet. Please note the frame holes aren't symmetrical, on each frame piece there has an arrow mark the arrow points to the top of the satellite, the frame with the 3/4 circle cut is supposed to go where the "Z+"

Now take 4 M2x5mm bolts, 2 female to female short spacers, and 2 female to male shot spacers. assemble the spacers as shown in the third image.