Sewing sleeves with opening at shoulder

Hi my monkey sweater has buttons on left shoulder and not seamed together. Now it wants me to sew in the sleeve Not sure how to do this. If it was seamed I would start on the seam and work the sleeve in. My thoughts was that the sleeve would actually be sewed in like the other side but the center of the sleeve would be attached at the shoulder seam without sewing shoulder seam together somehow.

Any help appreciated.:???:

If I understand what you have going the button and buttonhole bands will overlap…I’ve never done it myself and someone else will know the best way. I’d stitch the overlapping bands together at the shoulder opening and then do the sleeve the same as the other one.

That’s precisely the way to do it. Thanks, GG!
Here’s a photo of such a sleeve shoulder join in case that helps.
http://www.ravelry.com/projects/snichols16/button-shoulder-pullover-srk-143