How do you change the string on the echo srm-210?

To change the string on the Echo SRM-210 trimmer, first, turn off the engine and disconnect the spark plug for safety. Remove the spool by pressing the tabs on the sides and pulling it out. Replace the old line with a new string, typically 0.095 inches in diameter, by cutting a length of about 20 feet, threading it through the spool's eyelets, and winding it evenly. Finally, reattach the spool to the trimmer and ensure it's secured before starting the engine again.