executing a step from groovy script

I am passing my parameters to the request object in say "Step 1 - open" using groovy script. How do I run the script.
Below is my script


// get request property
def openrequest = testRunner.testCase.getTestStepByName( "Step 1 - open" );
def openrequestproperty = openrequest.getProperty( "request" );

// parse out textnodes to modify
def node = new groovy.util.XmlParser(false,false).parseText(openrequestproperty.value);
def textNodes = node["soapenv:Body"]["x:open"]["abc"][0].children()

// modify
textNodes.clear();
textNodes.add( "test1" + System.currentTimeMillis() );

// write back to string
def writer = new java.io.StringWriter();
def printer = new groovy.util.XmlNodePrinter( new PrintWriter( writer ));
printer.print( node );

// set property
openrequestproperty.setValue( writer.toString() )

testRunner.gotoStepByName( "Step 1 - open" );

Now how do I execute "Step 1 - open".

Any help will be greatly appreciated.

Anu