Find the shortest chain cutter link on your chainsaw using the slide caliper, which is similar to a compass. Slip it over each link and note the size of the links until you pinpoint the shortest link. Mark the shortest link with a piece of chalk. This is where you will attach the file guide.
Slide the open jaws of the filing tool over your chainsaw's bar and then tighten it in place by turning the two wing nuts by hand on the tool to the right.
Slip a screwdriver into the adjusting screw and then turn it to the right until it is centered on the chain.
Slip the file you are going to use to sharpen your saw into the body of the filing frame. Tighten down the adjustment screws.
Use the file to sharpen the first link, by brushing it in an up and down motion along the inside of the chain tooth. Continue sharpening all the chain links in this fashion.