How to change the blade on a craftsman scroll saw? The manual was been misplaced when we moved

You might be able to find the manual on the Sears site (this can be a frustrating search - but start with the model number). But even without the manual, this is pretty easy on most scroll saws. There is usually a plastic knob (about the size of a ketchup bottle lid) on top of the machine at the back. You loosen this knob a couple of turns (to the left) and the blade will become very loose. The blade is probably the "pin-end" type - it will have a little cylinder about a 1/4 inch long on each end of the blade. You can buy new blades at any home improvement or hardware store. Besides qualtiy, the main differences will be the length of the blade and the size of the teeth (expressed as TPI or Teeth Per Inch). You need more TPI for cutting harder and thinnner materials, less TPI for softer and thicker material. Put the new blade in like the old one was (teeth pointing down) and tighten the plastic knob. It's hard to be sure how tight is should be, since it doesn't suddenly tighten up. About a 1/4 turn past where is starts to get noticeably tighter is a reasonable place to start. If the blade pops off during use, it wasn't tight enough.