Bought pattern on etsy, downloaded to folder crafts/baby

After making the first 2 rows, I realised there is no way a 6 months baby head will fit through the neck opening. Making alterations to pattern to make a back opening that will be closed with button.

Chain 67 and DO NOT JOIN. Continue working back and forth in next rows.
Row 1 - dc in 4th chain from hook, 7dc, #3dc in same, 15dc, repeat from # 2 more times, 3 dc in same, 8 dc to end. Chain 3, turn.

Continue next rows increasing 1 dc in each 8dc section and 2 dc in each 15dc section.

On row 7, ss on top of ch3 and continue working in the round turning on each row.

Work underarms on row 10.

Work 5 rows in dc all around, turning on every row.
Piece should now measure 14.5 cm long and 20 cm wide. Continue to work skirt.

12 rows of shell stitches. Piece now measures 38.5 cm from shoulder, skirt measures 21 cm.

Yellow hem on skirt worked as pattern (measures around 6 cm). Total length from shoulder to hem: 45 cm; skirt length 26 cm.

Shoulder hem worked with 5.5mm hook and yellow yarn. Started with left arm in front dc row end after underarm ch space and finished at back without ss to ch2 (6 shells).

For bow chain 40.