First things first...measure the the width of the sleeve (the end). If you notice it is tapered (the width measure is smaller at the tapered end). Open up the seam. Shorten (cut) the sleeve. When you taper the sleeve to the exact measurements as they were, this will give you enough fabric for the new vent. The most important step is to taper the sleeve once you've cut the sleeve to the new, shorter length. Tapering gives you the extra fabric you will need for the vent. Hope this helps.
Barbara, September 2009
