This has me totally confused, and the figures in the instructions aren't helping matters.

6.1 is this saying to stitch the two 3" cutout together and leave the 1/2" inside corner unsewn?

6.5 I totally don't understand what it means by splitting 1/2" of the bottom corner. This makes no sense to me at all.
Life should not be a journey to the grave with the intent of arriving safely in a well preserved body, but to skid in broadside, thoroughly used up, worn out, and loudly proclaiming Wow! What a Ride!