Remove trigger pin with action un-cocked . http://www.histandard.info/manuals/sears/rfrifles/index.html
i think now the only way to find parts is to buy a used gun from someone to fix your own.
I'd check with Numrich Gunparts at the link >>>>
To disassemble a Stevens Model 59B shotgun, first ensure it is unloaded. Then, remove the forend by unscrewing the forend nut. Next, push out the trigger plate pin and remove the trigger plate assembly. Finally, push out the hammer pin and remove the hammer assembly to fully disassemble the shotgun for cleaning or maintenance. Remember to follow all safety precautions and consult the manufacturer's manual for detailed instructions.
To disassemble the J.C. Higgins model 583-1101 16 gauge shotgun, first ensure the firearm is unloaded and the safety is engaged. Remove the barrel by loosening the barrel nut or unscrewing any retaining screws, then slide the barrel off the receiver. Next, take out the trigger assembly by removing any pins or screws securing it in place. Finally, you can separate the stock from the receiver by removing the screws or bolts that attach them. Always refer to a detailed manual or guide for specific instructions and safety precautions.
Not recommeded for the casual owner. Find a good gunsmith.
I found parts for my model 29 at Numrich Gun Parts in New York. Their web site is e-gunparts.com
Disassemble to do what? To remove the trigger group you need to push out the two pins in the receiver to remove the trigger group. To remove the bolt you need to take the barrel off which requires an armorers barrel wrench.
There is a pin that has to be driven out. It passes thru the front section of bolt and is off-center
The wooden forend on that gun extends back along both sides of the receiver. There is a big honking screw that goes through the wood and the receiver from left to right. Remove that screw and you will be able to remove the trigger group downward and rearward. Please be careful not to lose the disconnector from the right side of the trigger group. Do not dry fire the trigger group. In fact, my advice is not to attempt to disassemble the trigger group unless you are very familiar with that action. It is easy to take apart, but difficult to reassemble. sales@countrygunsmith.net
Not very easily. The barrel is not designed to be removed by the user. With the gun empty, work the bolt to cock the hammer. Drift out the two pins that retain the trigger guard assembly and that can be removed. No further action dis assembly is advised.
More than one JC Higgins 12 g semi. and more than one set of instructions. You did not give us a model number.