once you remove the ribbing at the neckline, the neck curve will be too big. sew, following the shoulder seam and increase the seam allowance as you approach the neck. then it's very important that you stabilize the neckline to keep it from stretching again. you MUST use a facing on the inside or a decorative facing on the outside. if you don't know how to do this, PM me. a bound neckline will not keep it from stretching, since the binding has to be cut on the bias. if you try to cut the binding on the straight grain, it won't lay flat. it will try to stand up and it will pull the knitted fabric with it, pulling it out of shape again. on the front, where you cut it open, you need to add enough fabric to have an overlap for buttons, or a facing for a zipper unless you don't plan to close it. if you plan to remove the bottom and cuff ribbing, you need facings here also. it's true that you can use binding, but in my experience, binding doesn't stabilize as well, and can roll because the knit wants to roll. the binding is also lumpy. since i personally use a fabric overlap for a closure, i just match a fabric edging on the sleeve cuff and on the bottom. before you begin, make sure that it will be long enough if you decide to remove the bottom ribbing.