Added info:
In the instructions you will see place A to C and B to C

That places the ends from A towards top where * shoulder* is marked !
Now the corner where shoulder is marked comes in towards centre a bit too. So this gives you a armhole opening of 14-16 inches.
Once folded up sew it to your now shoulder section as you would wear it.

You will need about 600 gram of as many colours as you can find in left-over scrap yarns…