Removing a trimmer spool on a Toro 910 series trimmer is much like removing the cap from a spray paint can. The 910 series is an electric trimmer that uses a solid spool rather than a separate spool housing. The 910 series replacement spools are available through Toro.com or some home improvement centers. Installing a new spool is only a matter of snapping it back over the spindle until the spool locks into position.
Disconnect the electrical power cord from the Toro 910 trimmer.
Lay the trimmer upside down on a flat surface so the trimmer head is pointing toward you. Clean any grass clippings and dirt off the trimmer head with a dry cloth.
Locate the two slots on the bottom of the trimmer head by the feed bump. The feed bump is the portion of the head that you tap on the ground to feed more trimmer line as you are trimming.
Insert a large flat head screwdriver into one of the two slots. Press the screwdriver firmly into the slot and twist the screwdriver handle clockwise 1/4 turn.
Pull the spool straight off the trimmer and replace the line or perform any other repairs as necessary.