1. Solder the three 3-pin headers on the back first in the LIN/LOG positions - https://thonk.co.uk/documents/at-at-at/new_v2_kit/atatat-1.jpg
2. Next solder the three resistors into position (they are all the same value) - https://thonk.co.uk/documents/at-at-at/new_v2_kit/atatat-3.jpg
3. Next, put the three pots and 6 jacks into position, but don't solder yet - https://thonk.co.uk/documents/at-at-at/new_v2_kit/atatat-3.jpg
4. Put the panel on the front and secure a nut on the top pot and one of the bottom jacks.
5. Solder all the pot and jack connections.
6. put the red headers on the back LIN if you're mainly attenuating CVs, LOG if you're mainly attenuating audio signals. It's a subtle difference.
7. Mount in rack, you're done.