Darn...neither of my machines are that one. I have done a search and sure can't find much on that model, but I did find this, where you can buy manuals that you download for $3 or the free threading guide, which is here:
http://gotoes.org/sales/FreeThreadDiagramKenmore158.htm
It also tells on that page where to go if you want to buy the downloadable manual for $3.
I hope this helps! Good luck!