How do you clean an old Western Field pump gun model xnh 565-c 12 gauge improved cylinder?

your gun was made by Noble and is a model 60 or 66.make sure it is unloaded. release the pump and pull it rearward about 1 inch. unscrew the end cap of the magazine and remove the wood forearm. there may be a retaining washer under the mag screw that comes off with the cap or the forearm. inside the magazine under the cap is the shell stop, using a screwdriver or your finger, push it inside about 1\2 inch and give it a 1\4 turn and release the pressure. HANG ON ! THE SPRING AND STOP AND PLUG IF IT HAS ONE AND THE END CAP WILL COME OUT. if the last piece does not fall out turn the gun up and shake until it does. lay the pieces in the order they came out on your bench so you will remember how to put them back. the barrel should come forward out of the receiver and lay it to the side. this is usually enough for casual cleaning. press the slide activater bar rearward and open the action the rest of the way and clean the chamber, clean the barrel and the magazine tube and all parts. lubricate and return. if you want to go a little further without danger you can drive the two drift pins out located in the side plate of the receiver all the way through and remove the trigger group and clean lubricate and return. this is as far as you should go with out alot of experience with this type and model of shotgun. if you want to contact me via email i will scan and send an exploded parts view of your gun so you can see where everything comes from and goes back when you are done. good luck