On the trigger switch, if you look really closely you will see that there are clips inside where the wires go in. If you use a jewelers flat screwdriver or other narrow flat instrument, you can push the clip back enough to release the wire.

If the replacement cord doesn't have clips on the ends of the wires, make sure that you tin (apply solder) to the ends of the new wires before inserting them into the trigger. This is needed to keep the individual strands from being pushed everywhere and causing a short, and stiffens the end, making it easier to insert.

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