How do I fasten and change the guard unit on my Toro trimmer?

Take out the main spool’s housing parts by first gradually rotating it in the counter-clockwise direction inside the casing. Keep doing this till the primary gap within the line’s spindle mechanism has perfectly aligned itself to the marked notch present in the weed eater’s guard. You will now be capable of witnessing the presence of another gap also inside the motor housing. Carefully insert a screwdriver into the gap between all three holes in order to prevent the mechanism from accidently rotating – once you have done this, go ahead and rotate the spool in the other clockwise direction. When the main spool’s housing has been taken out of the unit, you can proceed to carefully unscrew all four screws surrounding the guard and holding it in position. After you have taken out the older guard unit, proceed to fasten the new one by re-tightening the screws around it and then ensure that you replace the housing back in position before you continue to use the unit. The guard may need to be replaced from time to time in the future, especially if the weed eater strikes a bark or stump during operation. Inspect the guard periodically to ensure that it is in good condition.