[Cecil]

You should have got a small screwdriver with "WAGO" written on the side. On the power distribution board, there are 2 slots, one on top, and one on bottom per individual connector. put the screwdriver in there as far as it will go while holding it horizontally. Now pull up on the screwdriver. A jaw in the bottom one should open, and you can put the wire in. At this point, you can release the screwdriver.

For the 40 amp breaker slots, the way the power flows is towards the small lightning bolt, meaning if you put a breaker into that slot, that is the one that will be powered. Hope this helps!