Sew two Unit #2s to a Unit #5 and label it Unit #8. You’ll need two of them and they ought to look like this:
Sew three Unit #4s together as shown below can call it Unit #9. This one is a bit tricky so be careful — you’ll need to make two of them.
Now sew the two Unit #6s to the Unit #7 and call it Unit #10. It will look like this: