Then carefully cut out the brackets from the plastic frame/sprue. It contains 6 short brackets and 2 long brackets, as well as 2 rails and 2 sets of Schürzen plates. A set of clippers is probably best for this, but remember to cut well away from the parts. Then trim off the excess plastic with a craft knife.
You can then dry fit (without glue) the brackets with the slots to make sure they fit well and don’t stick out at funny angles. The flat slot at the end of the bracket goes to the top. When happy with the fit glue them in. The long bracket glues to the front side of the hull as shown in the photograph. You want all the bracket’s slots to be level so the rail will rest on all of them. You can use a straight edge to ensure this.