Hi Anna.
You should cut two front pieces and four back pieces.
Sew these together as directed in the pattern and you will have two yoke pieces, an outer yoke and a lining yoke.
Place the two yokes right side together(so the seams are on the outside) and pin and sew as directed on the pattern sheet. Sew with a 1/2 inch seam allowance.
Trim and clip the seams,the pattern shows clearly how to do this.
You can now carefully pull the yoke through. Put your fingers in side from the front and hold the back yoke and slowly pull it through to the right side.
Repeat with the other back yoke.
Roll the seam gently under your fingers(it can help to damping it slightly)until the seam is flat.
Press it smooth with your fingers and then press well with the iron.
Good Luck Anna.
Nicole