Copy this ant-script into folder of your choise and execute it where your .tx folder exists like shown in the comment of the file

transifex-sync.xml

<project name="translations" default="full">
    <!-- 

    use this ant script to synchronize translated properties files from
    Transifex (www.transifex.com) into the working copy.

    Its possible to synchronize every translation file from Transifex or
    just a specific language. With an other option you can secify, which
    kind of properties will be synchronized (reviewed, translator or 
    developer - further details : 
       http://help.transifex.com/features/client/#user-client-08-mode)


    Options (as properties argument '-D'):

      tx.language : synchronize only the specifc language country code (see 
                    ISO 639-1 code at http://en.wikipedia.org/wiki/Language_localisation)

      tx.mode     : NOTE!!! This option requires transifex client tool in version 0.8++
                    mode to define which status the translated properties have.
                    
    execution examples:

     * sychronize every translated language

        <path-where-tx-folder-exists>ant -f <path-to-transifex-sync>/transifex-sync.xml


     * sychronize a specific language, in this case German

        <path-where-tx-folder-exists>ant -f <path-to-transifex-sync>/transifex-sync.xml -Dtx.language=de


     * sychronize a specific language and only reviewed properties, ignore all others

        <path-where-tx-folder-exists>ant -f <path-to-transifex-sync>/transifex-sync.xml -Dtx.language=de -Dtx.mode=reviewed

    -->

    <target name="init">
        <property environment="env"/>

        <!-- set geoserver root dir of cloned repository path -->
        <property name="tx.exec.dir" location="${basedir}/../"/>

        <echo message="Root folder where tx client tool will be executed is ${tx.exec.dir}"/>

        <!-- TODO check whether the .tx folder exists in geoserver root dir -->

        <condition property="tx.available" else="false">
            <or>
                <and>
                    <and>
                        <os family="unix" />
                    </and>
                    <or>
                        <available file="tx" filepath="${env.PATH}"/>
                        <available file="tx.exe" filepath="${env.PATH}"/>
                    </or>
                    <available file="config" filepath="${tx.exec.dir}/.tx/"/>
                </and>
                <and>
                    <and>
                        <os family="windows" />
                    </and>
                    <or>
                        <available file="tx" filepath="${env.Path}"/>
                        <available file="tx.exe" filepath="${env.Path}"/>
                    </or>
                    <available file="config" filepath="${tx.exec.dir}/.tx/"/>
                </and>
            </or>
        </condition>

        <condition property="tx.languageIsntSet">
           <not>
               <isset property="tx.language"/>
           </not>
        </condition>

        <condition property="tx.modeIsntSet">
           <not>
               <isset property="tx.mode"/>
           </not>
        </condition>

        <echo message="Transifex environment available : ${tx.available}" />
        <echo message="   if not, please check the path for the client tool" />
        <echo message="   or required config file at ${tx.exec.dir}/.tx/" />
        <echo message="   For further information visit Transifex help : http://help.transifex.com/features/client/"/>
    </target>

    <target name="full" depends="init">
       <antcall target="tx-all"/>
       <antcall target="tx-language"/>
    </target>

    <target name="tx-all" if="tx.languageIsntSet">
        <antcall target="tx-mode">
            <param name="language.option" value=""/>
            <param name="language.setting" value=""/>
        </antcall>
        <antcall target="tx-no-mode">
            <param name="language.option" value=""/>
            <param name="language.setting" value=""/>
        </antcall>
    </target>

    <target name="tx-language" if="tx.language">
        <antcall target="tx-mode">
            <param name="language.option" value="-l"/>
            <param name="language.setting" value="${tx.language}"/>
        </antcall>
        <antcall target="tx-no-mode">
            <param name="language.option" value="-l"/>
            <param name="language.setting" value="${tx.language}"/>
        </antcall>
    </target>

    <target name="tx-mode" if="tx.mode">
        <antcall target="tx">
            <param name="mode.option" value="--mode"/>
            <param name="mode.setting" value="${tx.mode}"/>
        </antcall>
    </target>

    <target name="tx-no-mode" if="tx.modeIsntSet">
        <antcall target="tx">
            <param name="mode.option" value=""/>
            <param name="mode.setting" value=""/>
        </antcall>
    </target>

    <target name="tx" if="tx.available">
        <echo message="pull -f --skip ${language.option} ${language.setting} ${mode.option} ${mode.setting}"/>
        <exec executable="tx" failonerror="true" dir="${tx.exec.dir}">
            <arg line="pull -f --skip ${language.option} ${language.setting} ${mode.option} ${mode.setting}"/>
        </exec>
    </target>

</project>