How to remove the trimmer head of a Stihl FE 55 electric edge trimmer?

Hold the blue piece firmly with your left hand, to keep it still.
twist the red piece counter clockwise with your right hand,

remove the spool of trim line





Then remove the deflector marked in blue, by loosening the bolt marked in red.
is this as far as you needed to go? If you want to go further

How to remove the trimmer head of a Stihl FE 55 el - 4bb1e839-5177-450a-b2fd-987f21bf43f2-dgd3mqdlwrxhi0ktu44qgfbm-3-9.jpegmqdlwrxhi0ktu44qgfbm-3-9.jpeg" alt="4bb1e839-5177-450a-b2fd-987f21bf43f2-dgd3mqdlwrxhi0ktu44qgfbm-3-9.jpeg" class="h_mi" /> Loosen the large bolt marked in red, this will release the drive shaft marked in purple, then remove the bolt marked in green and there is one more screw on top that is a short set screw that will need to be removed then you can remove the actual head of the trimmer .
GoodLuck!!!