Write PWM with only 8 bit? (Timer2)
Yes, Arduino Servo library uses Timer1 (and other ones, depending on Arduino boards) to manage FastPWM via software interrupts. Timer2 is used by tone() function: be careful if you are using that function.

A good example using Timer2 to generate PWM is the Infrared remote library for Arduino. If IR_USE_TIMER2 is defined it will use Timer2. The key code is at IRremote.cpp where the ISR is managed.