Stop winding when you have about 6 inches of string left on the end. Hook the string into one of the two notches on the rim of the spool. Replace the spool into the trimmer head, feeding the end of the string through the hole in the side of the head as you do. Set the spool on the pinion and rotate it until it seats properly.. The line of a weed whacker will often shorten and break due to use over time. Follow this guide to change the line on your Black and Decker 12-inch Grass Hog Automatic Feed String Trimmer (Model No.GH400). Before beginning this repair, make sure your weed whacker is off and not connected to power before trying to replace the line.
How to restring your Black & Decker Edger / Trimmer / Weed Eater. Replacement Lines on AMAZON: https://amzn.to/43iyhyn (affiliate link)How to install new tri.. If you want to replace the line on a Black and Decker trimmer, start by turning off the trimmer, unplugging it, and setting it down on a table or chair. Next, remove the cap on the trimmer head by pressing in the tabs on either side. Once the cap is removed, pull the spool from the cap and unwind the old line from the spool.