For nearly the last post in the conversion guide, the container locks and paint are the focus. The locks used on these wagons are not the same style as those on the VQCX wagons, so the locks provided in the kit can be stored for later use on another wagon.
What you'll need to do is get some small nails (or track pins, N scale ones work fine) and drill small holes to fit the pins though the deck of the wagon. Alternatively, you could use thin styrene rod, but that is not as hardy as the pins.
The containers I used to determine pin spacings are of the Ozfreight brand, as I've found these have the smallest distance in between the ridges that form the bottom sill on the containers, though any container you want to use will suffice. Make sure that your pins will sit just inside this ridge so the container won't move about on a moving wagon. You can either set the wagon up for one 40' and one 20' container, a 40'+ container, or three 20' containers. Then, once satisfied with the fit of the containers on the pins locations, you can drill the holes for the pins to come through. Superglue the pins in place once inserted and spacing is checked. Checking the spacings is probably the most important part of the process.
After the glue has dried, trim the pins down so they extend to 2mm above the wagon deck and test fit the containers again to check they don't move around. You can trim the pins a bit further if desired.
After the locks are finished and glued in, you can then paint the wagon in either SAR grey, ANR brown, AN green or the later NRC/PN liveries, with the code (when applied) altered to suit.