Help with Attaching Collar

I have knitted this :

Instructions for collar:

Cast on 39 sts. Work in k1, p1 rib for 2 rows. Cont in rib,
binding off 2 sts at beg of next 6 rows, 3 sts at beg of next
4 rows-15 sts. Work 2 rows even. Cast on 3 sts at beg of
next 4 rows, 2 sts at beg of next 6 rows. Work 2 rows
even. Bind off loosely in rib.

Looks like this:


Sew side seams. Fold collar in half widthwise and sew
folded edge around neck.

Here is the neckline:

I just can’t work out how to attach the collar!

Any suggestions appreciated.


Welcome to the forum!
The collar is folded in half and the long edges are sewn to the neck opening. You may have to stretch the collar slightly to fit the opening. Pin in place.
You could use one ply of the yarn to whip stitch the collar onto the opening.