What is the best way to re-string a string trimmer spool?

By hand wound very carefully.

Follow the arrow on the spool, and if a two line trimmer, cut about fifteen feet and bend it at the middle, actually leaving one side about four inches longer than the other. Then hook the center point on the spool, or through the spool depending on style, keeping line taut, wind to near the ends, reassemble onto the weed eater head.

Man, the simpliest things seem to be the hardest to put into words.