When I was in high school, my aunt and uncle gave me a sweatshirt to commemorate my Bob Marley phase (I'm still in it, by the way). I always loved the design and super soft lining of the hoodie, but it was a boys' XL and it was so baggy that I felt a little self conscious wearing it in public (think Bob Marley bowling ball). Also, I don't like wearing shirts that come right up to my neck--like crew necks--but I couldn't cut a split in the neck of the sweatshirt like I do with all my other ones without destroying Bob's image. So I decided to turn it into a sort of fitted, boatneck sweatshirt.
I started by carefully removing the ribbed waistband and cuffs from the bottom of the shirt and sleeves, respectively. Then I cut off the hood, leaving as much room above the printed image as possible. I wanted the shirt to have baseball-tee sleeves so I wasn't terribly careful in removing the sleeves since I would be re-cutting them rather dramatically. Once the sleeves were off, I took in the side seams until the shirt had the fit I wanted--still a little loose, so I could wear a shirt underneath, but fitted enough to get rid of the distinctly spherical shape it gave me before. With the shirt taken in, I started the process of reattaching the sleeves.
First I cleaned up the neckline, making sure it was symmetrical. I didn't necessarily have the final neckline I wanted, but it needed to be the same on both sides before I could set the sleeves. I cut each side of the shirt on a diagonal line extending from the armpit to the neckline. Then I positioned the sleeve under this diagonal line with the top corner of the sleeve resting at the neckline, and rotated the sleeve as needed to get the bottom of the sleeve to just meet the armpit end of the diagonal line. Once the angle of the sleeve was just right, I used the cut along the shirt as a guide to cut the sleeve on a diagonal as well. This made 3/4 length baseball-tee sleeves. I attached the sleeves, then cut the neckline to my desired shape.
With a few more adjustments, taking in seams here and there, I was ready to finish the shirt. I sewed the ribbed material back on the the bottom of the sweatshirt and the cuffs. Then I finished the neckline so the raw edge wasn't exposed. I'm so excited to be comfortable in my Bob Marley sweatshirt; I only wish this had occurred to me a few years ago! I have a sloppy zip-up hoodie that I might try something similar with. It's so satisfying (and cost effective) to create like-new clothes out of what's already in my closet. Be creative and enjoy!