As Noel says take the "square" ended part in picture 2 which is the end of the steering cable and carefully feed it through the circular hole in the side of the transom clamp (sitting just above the wood on your stand). Before you do this clean the tube really thoroughly, rust tends to accumulate here, liberally grease the metal tube before inserting. Don't bend this tube when fitting it (some transoms can be awkward space wise).
A large metal nut prefitted to the steering cable then holds it in place. You may (probably should) have a plastic nut on the other side of the engine with an o-ring seal in it.
The other part in picture 2 looks like it simply bolts to the square end with a slightly loose nut and bolt (usually a nyloc nut, and washers as necessary). Again ensure well greased.
Looking at picture 3 you may need to refit that black arm (the thing we can see the end of in pic 2) the otherway up - as from that angle I don't think the two parts in pic 2 will meet otherwise. Mine is mounted centrally (no choice) - not sure if yours is offset and if so what advantage / disadvantage that brings.