Small Engines (Lawn Mowers, etc.): adjusting brakes on murray riding mower, murray riding mower, hex nut

Question
How do you adjust the brakes on a murray riding mower. I did what the instructions said. Put in nutral, engage the parking brake, and adjust the hex nut. The nut wont adjust. Should I replace the brake pad? How do you remove the brake pad?

Answer
 Hello Robert:

 Send me the Model Numbers Off of the Mower, Please. I May be Able to Locate a Diagram that will Assist in this Repair. There are Diffrent Styles of Brake Assemblies and Removal of the Pads Depends on the Model. Thanks.

 Respectfully

 John