There may be a fuse on the back of the instrument cluster, this may be a good place to start. It resembles a bulb but it is red in color.

If the brake lamp goes out when you lift the brake pedal slightly it may require a new main brake cable. The nylon liner on the cable seperates and causes it to drag inside the outer housing just enough to keep the pedal from reaching the stop. A rather involved repair if it is indeed the culprit.