How do you take a 12 gauge apart?

To disassemble a 12-gauge shotgun, first ensure it is unloaded and remove any ammunition. Then, depending on the model, you may need to open the action and locate any release mechanisms for the fore-end and barrel. Typically, you can remove the barrel by unscrewing or depressing a release lever, followed by sliding off the fore-end. Finally, consult the manufacturer's manual for specific instructions, as designs can vary significantly between different shotguns.