Modifying to a round neck at the front.

For tapered sleeves, I cast on 8 less sts than the pattern called for and increased two sts either edge of second green stripes 4 times. Then on the other side I bound off 8 sts total on the second green for four stripes of the end of the sleeve to match the beginning of sleeve.

Front neck
Cast off 3 sts first p row
cast off 2 sts second p row
Cast off 2 sts third p row
cast off 1 st forth p row
cast off 1 st fifth p row (56 sts)
knit straight until 10 rows left then
cast on 1
cast on 1
cast on 2
cast on 2
cast on 3

Ran out of green.