The Ariens ST633 string trimmer, heavy-duty model, trims even the tallest, toughest weeds and grasses. It has a 22-inch cutting diameter, a heavy duty deck frame, fold down handlebars and a 15-degree pivoting head to make it easier to reach tight spots when trimming. Replace its trimmer line when it extends less than 4 inches from the cutter disk. Ariens recommends only using Ariens replacement trimmer line.
Turn off the engine and pull the spark plug out to disconnect it.
Pull the worn trimmer off the cutter disk.
Cut a piece of line with a pair of sharp scissors 1 to 2 inches longer than the string you just removed from the trimmer.
Push one end of the line through one of the holes in the cutter disk. Repeat with the other end of the line and push through the other hole.
Cross the line and push the ends into the two holes on the cutter disk's side.
Readjust the line so that the line ends extend at the same length.
Pull the line tight and cut the ends of the line if too much slack remains.