Fabricating the trim cable retainer clip.First drill the horizontal marked locations with #40 bit followed by 1/4" bit on the vertical pre-marked location.Then cut off the top of the vertical flange 1/2" from the bottom (through the centerpoint of the cablr hole). Secondly, cut the remaining vertical flange material 1-3/32" from each end of the clip. Finally using a pair of duck bill plier, bend the retainer tongue to 105 degrees. Here, i checked the angle with the cardboard angle template made earlier on.