how to transform xml file to graphml file

Question

<?xml version="1.0" encoding="ISO-8859-1"?>
<fmiModelDescription
  fmiVersion="1.0"
  modelName="bouncingBall"
  modelIdentifier="bouncingBall"
  guid="{8c4e810f-3df3-4a00-8276-176fa3c9f003}"
  numberOfContinuousStates="2"
  numberOfEventIndicators="1">
<ModelVariables>
  <ScalarVariable name="h" valueReference="0" description="height, used as state">
     <Real start="1" fixed="true"/>
  </ScalarVariable>
  <ScalarVariable name="der(h)" valueReference="1" description="velocity of ball">
     <Real/>
  </ScalarVariable> 
  <ScalarVariable name="v" valueReference="2" description="velocity of ball, used as state">
     <Real/>
  </ScalarVariable>
  <ScalarVariable name="der(v)" valueReference="3" description="acceleration of ball">
     <Real/>
  </ScalarVariable>
  <ScalarVariable name="g" valueReference="3" description="acceleration of gravity" 
                  variability="parameter" alias="negatedAlias">
     <Real start="9.81" fixed="true"/>
  </ScalarVariable>
  <ScalarVariable name="e" valueReference="4" description="dimensionless parameter" 
                  variability="parameter">
     <Real start="0.7" fixed="true"/>
  </ScalarVariable>
</ModelVariables>

<Implementation>
  <CoSimulation_StandAlone>
    <Capabilities
      canHandleVariableCommuni 
 cationStepSize="true"
      canHandleEvents="true"/>
  </CoSimulation_StandAlone>
</Implementation>
</fmiModelDescription>

This is my xml file, i want to convert it to graphml file, i searched for xslt, but i didn't find many documents about this conversion. I am very new here, so can anyone help me?