STEP 4. (OPTIONAL) Add width at the hips
I only really recommend this if you want to add buttons to close the cardigan, but especially if your hip measurement puts you in a size larger than your entire chest; Since the pattern was designed to hit the high hip, it does not curve outward at all to accommodate the hip. To solve this problem, I suggest adding a little width at the hips, perhaps 1-2 inches on each piece (shown in yellow in the diagram above).
This isn't shown, but I also suggest you curve your line a little at the bottom so that the corner is still true (perpendicular) at the hem; in other words, where the side edges and hem meet, you want it to be at 90 degrees so you don't have a weird stitch at the bottom of the side seam.
STEP 5. Cut out your pieces and sew your cardigan
The next step is simply to construct your cardigan as the pattern indicates.