The governor needs to be in the cover to install, but the arm is in the wrong position in your picture, it should be in toward the cylinder. To get the pin in the spool remove the circlip on the end of the kips shaft, remove the spool, use a 10mm wrench on the arm and pull it away from the cylinder, then put the pin in the spool and as it return slide it on the kips shaft, then put the circlip on. the alternative is to remove the bolt on the governor shaft, slide the pin in the spool then tighten the bolt.