need Kenmore sewing machine model 158, I need to know how the bobbin works. It feel out with the casing and I don't know how to get it back in and how to thread it through the machine. I also don't know how to use the different stitches. The machine is 31 years old. I started sewing when my son was born and haven't touched it since. I really need the manual or the closest model. The machine is like new and now I'm retired and want to sew.