Divide for Neck Opening:
Next (dec) row (RS): *P1, sl 3 sts to cn and hold in back, k2, ssk over next st on LH ndl, and first st on cn, k2 from cn, p1; rep from * 19 (22, 24, 26) times - 140 (161, 175, 189) sts.
Sl marker, k1, cast on 3 sts purlwise--- 143 (164, 178, 192) sts. Turn. Work back and forth in rows from this point. Keeping 4 sts opn right edge of neck opening and 1 st at left edge of neck opening in Garter st, work 3 rows as est.
I'll give it a shot--
P1, slip 3 stitches to a cable needle and hold in back.
Knit the next 2 stitches from the left hadn needle, then do a ssk, using the next stitch on the left needle and the first stitch on the cable needle, then knit the remaining 2 from the cable needle and purl 1.
Then you repeat this however many times that works for your size.
For the next step, slip your marker, and cast on 3 stitches. Now you will work all the stitches back and forth as if you were knitting flat, keeping the correct stitches at the edges in garter stitch while you work in pattern for the rest of the stitches.