I started out with a collar and here is the pattern:
Cast on 61
Knit 14 rows ( 7 garter ridges)
15th row: K4, (K2tog) 26 times, end K5.
16th row: K2, (YO, K2tog this is a buttonhole), Purl to last 4 sts, K4.
17th row: K4, inc ( knit in front & back of stitch) in next 26 sts, end K5
18th row: K4, purl across to last 4 sts, K4.
This eliminates the neckband portion of the pattern. continue on with Row 1 where it reads "begin pattern as follows".
I just realized you might want to place the buttonhole on the other side so just remember which end to do that!
I also eliminated rows 13-18 of the sleeves and worked 6 rows of K1, P1 ribbing.
This is the 1 year size.
I would like to try this same pattern using baby weight yarn, just have to work out the numbers and lengths.
I have another sweater almost done( Suzanne's Matinee Jacket) I'll post a picture of it, hopefully tomorrow!