CS-550EVL Echo Chainsaw - Overview

Hello Reuben, thank you for your question! To install the throttle, follow the following instructions: 1. Depress the handle cap retaining tab and pull the handle cap off. 2. Drive the trigger pin out of the handle housing. 3. Lift out the trigger and spring, and prepare the new throttle trigger. 4. After first transferring the spring from the old trigger to the new one, insert the new trigger into the handle. 5. Reposition the handle cap and snap it into place. We hope this information helps!