Cutting:
Cut the pattern pieces from your outer fabric. Lay the fabric right side up. Place the selvedges parallel to the center so that you can place the front, back and front yokes in the fold. The pattern pieces should all lie face up. Always align the thread arrow in the same direction on all pieces and parallel to the selvedge of the fabric. Transfer all clips from the pattern through a 3mm long incision with scissors or chalk and mark the ends of the darts from size 40 on the smooth version, note that bust darts must be used for larger sizes. In the variant with the pleats, the dart is completely omitted. Clip the seam allowance in the fabric fold because this is always a center. Markings define positions of dart ends, pocket positions, and much more. Transfer these either with chalk or pins. 
To sew these sweaters you will need a sewing machine and an overlock sewing machine, or alternatively the zigzag stitch on your sewing machine to neaten the cut edges.
Be sure to use a jersey needle and use a stretchy stitch, i.e. if you are sewing with a household sewing machine, you should use either a zigzag stitch or the three-part elastic stitch and then all seam allowances again with a zigzag stitch or another appropriate stitch Neaten so they don't fray. In addition to the description, the colorful lines in the pictures show you where a seam needs to be sewn or something needs to be glued.
When sewing, pay attention to the seam allowance included in the pattern.
Have fun sewing! 
First, neaten the side edges of the front and back pieces, as well as the sleeves. 
Next, place the pleats in the front piece and sew them in place at a quilting foot width. 
You can then sew the front yoke and the front piece together, right sides together. Finish the seam allowance and press it up. 
Now you can sew the front and back pieces together at the shoulders, right sides together, and finish the seam allowance together. Iron the seam into the front piece. 
Next you need the collar. Sew this together right sides together, iron the seam apart and fold the collar together so that the seam is on the inside. 
Now you can insert the collar into the neck hole. Pin it right sides together (the seam is pinned to the center back) and sew all the way around. Finish the seams back together. 
Your part is ready so that you can insert the sleeve. Place the sleeve right sides together at the appropriate armhole (the clip in the front must match the clip in the sleeve) and sew it in place. Finish the seam allowance again and iron it into the sleeve. 
Now you can sew the side seam together and iron the seam apart. A tip: I would iron the seam allowance of the hem inwards beforehand. 
Now all that's missing are the cuffs. You sew these together right sides together and then fold them over so that the night allowance is on the inside, just like on the collar. 
Sew the cuffs to the sleeve, right sides together. Make sure that the cuff seam and the sleeve seam line up. 
Finally, just sew the hem in place.
