Since Kwik Sew 3884 didn’t go up to my husband’s size. (the largest size is one size smaller than he wears) I needed to size it up one size.
I started by tracing it in the largest size and marking everything including both spots for lengthening.
If this was just pajama pants I would have widened it at the side seam and left everything else alone. But since I needed to up a size I cut my tracing on both lines for lengthening and in half down the center. which made for 6 pieces, which I taped to the table with 1 inch spacing to add the desired length and width.
Then I traced the pattern pieces to create my new sized up pattern piece.
I did this with both the back and front pieces, I was able to just add the length to the waistband and fly pieces. No other pieces needed changes, but I did draft a jeans pocket to use instead of using the trouser style pocket.