First cycle the gun making sure the barrel and magazine are clear of shells and the safety on. This is necessary to have the bolt and trigger mech in the right position to disassemble the easiest. Set the gun on the floor with the trigger facing you.
Next go to the top of the magazine and push the roll pin towards you. Then rotate the magazine tube counterclockwise until it stops about 1/2 turn.
Pull up on the magizine tube and forearm. Make sure the slice is pulled out past the receiver. Then turn the barrel and mag tube counterclockwise. This will separate the barrel and receiver.
Place receiver on its back with the trigger up. Remove the screw and slowly pull the trigger assembly up and back. Watch for the shell stop and make sure it does not fall in and bind if your gun has a shell guide on the trigger mech.
Next with a small flat screw driver remove the shell stop for the side of the receiver. Take notice of how flat it sets when in the proper position.
Then using the same small flat screw driver remove the retaining spring that is in the side of the receiver behind the bolt. Be carefully and do not pry and twist to remove simply get under it and lift up the reach in and slide it towards the back of the receiver. pay attention to how it comes out and put it back in the same way on assembly.
To remove the bolt keep receiver on its back and look opposite the shell slot there is two little tabs on the bolt next to the receiver wall. Using the screw driver move the front tab away from the reciever wall back towards the bolt. The bolt will then pop up and back.
Slide the bolt back and lift out.
Using an air hose the trigger assembly can be cleaned without taking it apart. I usually slowly release the hammer for better cleaning.
To reassemble, put the bolt back in then reach in and depress the firing pin button on the back of the bolt while pushing down and foreword. The bolt will lock into place. While holding it down move the back tab towards the bolt.
Then put the barrel and mag back on by reversing the removal directions. You should be able to use the pump slide to lock and hold the bolt. Simply pump the action and push forward hard. You may have to move the tabs along side the bolt to allow the slide to grab the bolt.
Then install the retaining spring. Place the spring in the slot, place your finger over the spring and push down and slide foreword. It will not go in unless the bolt is in the closed position.
Place the gun on its side, place the shell stop in and using two fingers one on each side of the center stud, move your fingers opposite of each other until it sets into place. Some guns because of wear may require the bolt to be moved back some to this to line up.
Once this is in place install trigger by slowly sliding it at an 15 degree angle. When you have the trigger in about 2/3rds of the way lift up on the front and bring the back down. It should sit right into place.
DO NOT FORCE THE TRIGGER INTO THE RECEIVER!
This can cause the shell stop to dislodge and be bent if you try and cycle the action.
It will take you some time to do all of these things, but after a few times you will be able to do this blindfolded just by feel. It may sound complicated but it really is a very easy gun to disassemble and reassemble.