You'll need to set an IBOutlet reference from the TableViewController back to the button. IBAction denotes a message the button will send the target. IBOutlet denotes a reference back to the control itself.
The process is similar to the process you (maybe) used to create the IBAction in the first place. Add a line "@property (nonatomic, weak) IBOutlet UIButton* button;" to your TableViewController.h file. Then in Interface builder, control-drag from the TableViewController to the button and select the outlet from the popup.
FWIW, it's usually bad UI to hide an inactive button, better to just disable it. (enabled = false)