How do I change the starter cord on a Ryobi 725r gas line trimmer?

The string starter on my trimmer broke. The only thing keeping me from being able to replace the starter string is what looks to be the centrifugal clutch. How do I get this off so I can take the plastic cover that's covering the string starter off?How do I change the starter cord on a Ryobi 725r gas line trimmer?
take the cord housing off by removing the screws that hold it on. . Unwrap the old cord being careful not to let the spring come loose. wind the new cord around in the opposite direction as you toke the old cord off. reattach with the screws.g