Last year my son, bless his scavaging little heart, found a Scotts Silent
lawn mower someone was discarding. I have used it number of times and
really like it. I can't run anymore because of bad knees, and this gives a
pretty good workout; as well as giving the lawn a break from the rotary
lawnmower.

It is really really dull. How do I go about sharpening it? (still seem to
cut pretty well though)