Kate - I don't see that you have received an answer, so here goes: Grab the "knob" in the center of the spool and pull straight out; it is held in place by clips. You can buy replacement pre-wound spools or you can buy the line and rewind your own; it takes a .065mm line. If rewinding, note the direction arrow on the bottom of the spool. To replace, feed line through the grommetted hole, then, being careful to keep the line from slipping out of the spool and below the spool, snap the spool back in place; this may take a bit of force.
Mary in Maine
August 2010