Remove the entire shutoff solenoid assembly leaving an arm that will then swing by hand. I use springs to pull mine all the way forward into the run position, and pull my cable to swing the arm back to kill the engine. You can try it by hand before you install to see what i mean. Forward to run, back to stop.
I'll try to take and post pics of mine which has the set screw welded to the bracket. Leave extra cable that you can fold around the set screw so it won't pull through the eye.