I have seen several post asking for information on dis-assembly and cleaning of the Stevens 311 or associated other models like a JC Higgins Model 101.7 or Westerfield Model 530A. While a dis-assembly guide book is always good to have it is not absolutely required on this shotgun. If you have any gun action dis-assembly experience and pay attention to what you are doing you can do this gun. BE SURE THE GUN IS NOT LOADED - CHECK IT AGAIN. Remove the forearm by pulling down on the forward tip and it will pry off under some spring tension but is easily removed. Once you have removed the forearm open the gun and remove the barrel. Removing the stock will require a long, wide blade screw driver to remove the the large screw hidden under the butt plate. At this point, you can begin an inspection and dis-assembly of the receiver. Assuming the action functioned properly to begin with and your effort is a thorough cleaning then I recommend the following. If the action appears in good condition but perhaps just dirty then I would suggest not dis-assembling it but soaking it a day or so in a solvent like kerosene, WD-40 or whatever you prefer. Water based kitchen degreasing cleaners like 409 work but I don't recommend a soak in them and they should be followed by blow drying and soak in an oil based solvent. If you have a friend with a parts washer that is a great option. If the receiver is rusty or gummed up then it is best to disassemble and clean. It usually isn't necessary to strip everything out and I would leave the triggers and safety mechanism as it isn't necessary to remove them to clean then. Usually. These are the steps I follow for the main parts.
1. Take a small screw driver, insert it in the slot where the barrel locks, depress the catch to release the lever back to the center position.
2. Unhook the sear springs which take the tension off the sears and makes it easy to drift out the pin. Remove the pin L to R. Remove these parts and set them aside to soak.
3. Insert a rag through the receiver so that nothing will fly out when you remove the hammer pin. It usually will not fly out but having a rag wrapped though the tang opening eliminating surprises.
4. Drift the hammer pin out L to R, removing one part at a time. Take out the left hammer when it is free, then the cocking lever or yoke, then the right hammer. Organize your parts in groups to soak. I do this as routine even though in this gun it is obvious what parts can only go left or right.
5. With the hammers out the hammer springs and plungers will be revealed beneath them. Take them out an organize them with the hammers. Note that in some models there is a small silver colored washer in the bottom of each plunger spring hole. Sometime the stay in and sometimes fall out. Watch where they are and be sure you put them back in, flat, to receive the shaft end of the plunger.
6. With all this out you will have access to the firing pins. It is intuitive how they remove. Each has a tiny hair like spring. Don't loose them.
7. At this point you have as much apart as is usually required for thorough cleaning. It usually isn't necessary to remove the latch but that is your choice.
8. Reassembly is the exact opposite of the above order. Take your time to be sure everything is positioned correctly as you put it back, especially the springs. It is CRITICAL that the slots in the end of the plungers be oriented to receive the spur on the hammer. The spur is on the opposite side of the hammer from the sear hooks. If the hammer is not seated properly in the plunger slot then the gun will not cock and you will have to dis-assemble the parts all over again. Getting this orientation correct and seated properly is the hardest part of this whole operation because you can't see the slot when the hammer is inserted over it. Even with great care I have had to dis-assemble a gun three times to get it right.
A padded vise is helpful but not totally necessary. You will need a good set of punches, a brass hammer and a few tiny screw drivers for unhooking springs and helping to align holes. You can do this. Good luck and pay attention to what you are doing.