how to drive DC motors on UNO pin 5 and 6

some1 put an article about it but i cant understand what he said. the link is http://playground.arduino.cc/Main/TimerPWMCheatsheet

Example: DC motor drive on the Arduino UNO, pins 5 and 6

For Fast PWM of 62.500 kHz (prescale factor of 1) Use these two lines in the setup function:

TCCR0A = _BV(COM0A1) | _BV(COM0B1) | _BV(WGM01) | _BV(WGM00); TCCR0B = _BV(CS00);

And modify the line in the wiring.c function in the Arduino program files hardware\arduino\cores\arduino\wiring.c :

define MICROSECONDS_PER_TIMER0_OVERFLOW (clockCyclesToMicroseconds(1 * 256))

For Phase-correct PWM of 31.250 kHz (prescale factor of 1) Use these two lines in the setup function:

TCCR0A = _BV(COM0A1) | _BV(COM0B1) | _BV(WGM00); TCCR0B = _BV(CS00);

And modify the line in the wiring.c function in the Arduino program files hardware\arduino\cores\arduino\wiring.c :

define MICROSECONDS_PER_TIMER0_OVERFLOW (clockCyclesToMicroseconds(1 * 510))

can some 1 tell me how to make it?