Yes, after row 19, start with row 4 but with the shaping decreases. But then you work 7 rows of the pattern without any decs. So on row 6 you don't do them, but since you already decreased on row 4, start with k2 and you should end up with 3 sts at the end. Row 8 starts with k3 and you end with just k2, don't do the YO.
sue- knitting heretic