Toro Revolution 66110T Operator's Manual page 23

4. With the metal rod securing the trimmer head, rotate the trimmer
head clockwise to remove it from the threaded gearcase post
16).
5. To install the new trimmer head, rotate it counterclockwise onto the
gearcase post while securing the cup plate using the metal rod.
Figure 16
Some parts not shown for clarity
23
(Figure
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