Ant TestNg for jenkins

build.xml

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<project basedir="." default="build" name="Ant Play">
    <property name="classes.dir" value="bin" />
    <property name="report.dir" value="test-output" />
    <path id="classpath">
        <fileset dir="lib">
            <include name="**/*.jar"/>
         </fileset>
        <pathelement path="${basedir}\${classes.dir}"/>
    </path>
    <target name="init">
        <mkdir dir="${classes.dir}"/>
        <copy includeemptydirs="false" todir="${classes.dir}">
            <fileset dir="src">
                <exclude name="**/*.java"/>
            </fileset>
        </copy>
    </target>
    <target name="clean">
        <delete dir="${classes.dir}"/>
    </target>
    <target depends="clean" name="cleanall"/>
    <target depends="build-project" name="build"/>
    <target depends="init" name="build-project">
        <echo message="${ant.project.name}: ${ant.file}"/>
        <javac debug="true" includeantruntime="false" destdir="${classes.dir}">
            <src path="src"/>
            <classpath refid="classpath"/>
        </javac>
    </target>
    <target  depends="build" name="runTests" description="Running tests" >
        <echo>Running Tests...</echo>
        <taskdef resource="testngtasks" classpathref="classpath"/>
        <testng outputDir="${report.dir}"
            haltonfailure="true"
            useDefaultListeners="false"
            listeners="org.uncommons.reportng.HTMLReporter"
            classpathref="classpath">
            <xmlfileset dir="${basedir}" includes="testng.xml"/>
            <!--<classfileset dir="${classes.dir}" includes="**/*.class" />-->
        </testng>
    </target>
</project>

http://stackoverflow.com/questions/16782414/how-to-run-testng-tests-on-jenkins

Can you please let me know stepwise Approach.
Thanks,
Ajit Jadhav.