Öncelikle ilgili dosyada şu kodu bul:

<script type="text/javascript">
    var so = new SWFObject("flvplayer2.swf","single","512","322","7");
                  so.addParam("allowfullscreen","true");
                  so.addParam("allowscriptaccess","always");            
                  so.addVariable("file","http://www.avcilarsitesi.com/index.php?p=External/Player");
                  so.addVariable("height","322");
                  so.addVariable("width","512");
                  so.addVariable("location","flvplayer2.swf");
                  so.addVariable("showdigits","true");
                  so.addVariable("autostart","true");
                  so.addVariable("overstretch","false");
                  so.addVariable("bufferlength","3");
                  so.addVariable("type","flv");
                  so.addVariable("usekeys","true");                                
                  so.addVariable("skin","flashskins/flashskins8blue.swf"); 
                  so.addVariable("logo","images/playerlogo1.png");                         
                  so.write("flashcontent_1973");
</script>

ve şu kod ile değiştir.

<script type="text/javascript">
    var so = new SWFObject("flashskins/flashskins8blue.swf","single","512","322","7");
                  so.addParam("allowfullscreen","true");
                  so.addParam("allowscriptaccess","always");            
                  so.addVariable("file","http://www.avcilarsitesi.com/index.php?p=External/Player");
                  so.addVariable("height","322");
                  so.addVariable("width","512");
                  so.addVariable("location","flashskins/flashskins8blue.swf");
                  so.addVariable("showdigits","true");
                  so.addVariable("autostart","true");
                  so.addVariable("overstretch","false");
                  so.addVariable("bufferlength","3");
                  so.addVariable("type","flv");
                  so.addVariable("usekeys","true");                                
                  so.addVariable("skin","flashskins/flashskins8blue.swf"); 
                  so.addVariable("logo","images/playerlogo1.png");                         
                  so.write("flashcontent_1973");
</script>

Şu url üzerinde Mozilla Firebug eklentisi üzerinden denedim ve çalışmakta. Şu linkten de çalışmış olduğuna bakabilirsin. Kolay gelsin...