Stihl Replacement Bump Head Spools For FSA 56, Mowing HeadAs you use your STIHL trimmer through the years, you will need to swap out trimmer heads and blades from time to time. Before getting started with a replacement, make sure you read through the instruction manual that came with your trimmer. After going through your manual, you can also use the videos and instructions below to help with trimmer head and trimmer blade replacements. Be sure to wear the proper protective gloves while working on your