I'm not an expert, but what I do is take a compiled design into my Embroidery SW and redraw the portion that I don't like and then delete the other layer. Does that make sense?

I've not found a way to change the width in Editing software, just like Simplyrosie I use the Digitizing part of my sw to redo something. That applies to Husqvarna 3D pro as well as Embird, no idea about other sw.

What kind of software do you have, the name brand, and what does it do? Can you just change formats and colors, or can you actually change stitches and digitize with it? If it is digitizing software, you should be able to find the "properties" of the satin stitch line, and change the width. In my Janome Digitizer Pro, I can highlight the object, such as the satin line, right click, which gives me a menu, choose "properties" from that menu. Then it gives me a screen where I can change the stitch width and length, density, feathering, etc. I hope this helps you some. To you, and everyone, the more information you can give about exactly which machine, software, etc. you are using, the more help one of us may be able to be to you. They're all so different, hard to say without knowing. Best of luck to you, hugs, Marji