Unload the pistol and gently push the muzzle against a firm surface. The cannon assembly will retract about 1/4", then rotate the lever below the side plate 90 degrees. Let the upper return to it's extended position and remove the side plate. Once the side plate is off you can then slide the upper off the frame. To remove the toggle simply remove the rear pivot pin and pull the toggle out from the back. To remove the firing pin use a wide thin screw driver or Luger tool , push in ans rotate counter clockwise. If you need to remove the hold open for any reason you simply pull it up and out as it is held in with a spring and a U hook on the back. When reinstalling the toggle you will need to push in the sear bar to disengage the striker.
Reassembly is the opposite of dis-assembly. When you put the upper back on, make sure that you turn the upper upside down with the S hook pointing out. Slide the upper on until it gets close to the main spring lever and turn the pistol over. This will allow the S hook to properly engage the hooks.
Try www.lugerforum.com .