How do you get the drum brakes off a 1988 Mazda 323 dx the bolt looks pinched in on two sides and wont turn?

The nut is flattened to prevent it from working loose during driving. The left hand side has a left-hand thread so you need to rotate the nut clockwise (rotate right). It will take a bit of effort as you have to overcome the deformed portion of the nut. The right hand brake has a right-hand thread, so rotate the nut counter-clockwise (to the left) to remove. Cheers Malcolm