You grasp the forend at the front tip and pry it off. It is held in place by spring tension.
The model 5100 Stevens shotgun has a plastic stock
Try e-gunparts.com
Remove buttplate. Use a socket extension and rachet to unscrew the stock bolt (it's in that hole in the center of the butt)
Impossible to answer on the internet without detailed pictures.
Boyd's stocks on the net.
Try e-gunparts.com
To take apart a Stevens Model 311 double barrel for stock replacement, first ensure the shotgun is unloaded and the safety is engaged. Remove the forend by pushing the release lever and sliding it off the barrel. Next, locate the stock screw at the rear of the receiver, unscrew it using an appropriate screwdriver, and then gently pull the stock away from the receiver to detach it. Be cautious to avoid damaging any internal components during this process.
To disassemble an Iver Johnson .410 shotgun, first ensure the firearm is unloaded. Open the action and remove the forend by pushing the release button, which is typically located on the underside of the forend. Next, unscrew the barrel from the receiver using the barrel nut, and then you can separate the stock from the receiver by removing the stock screw. Always consult the specific model's manual for detailed instructions and safety precautions.
If the owner's manual doesn't have instructions, seek out a qualified gun smith.
The gun was built by Savage/Stevens for Sears, and is basically the Model 311. There were several different types of forend used on this model. We can probably supply the part, need to know if you require only the wood or the entire assembly including the forend iron. repair@countrygunsmith.net
I bought one about seven years ago, synthetic stock and forend, for $125.
Remove the forend, then the barrel. The serial number will be on the underneith side of the bottom barrel at the point where it hinges with the rear stock. You may need a magnifying glass.