how to change servo motor PWM

[Archangel]

pin   var yourport.x ' for instance PortB.7
Duty  var byte
cycle var byte

PWM pin,duty,cycle ' right out of the book 
 . . . . . . Or,
PWM PORTB.7,127,100 ' RIGHT FROM THE BOOK 50% duty cycle @ 100 cycles

Alter the values in the variables to change the values of the Duty time and Cycle time.
you can change them using digital methods or analog a/d converters and a potentiometer.

to alter numbers just . . . duty = 130
.................................. cycle = 150