500 Error after adding tracking code

[andy871@.....com]

I just added google tracking code in OPC for confirmed orders & upon clicking save I got a 500 error message (copied below).
Now I cant access any part of the back end of my site, not even to remove the code.

Have you seen this error before & how can I remove this code maybe from FTP or via phpmyadmin.

Any ideas greatly appreciated as this is a live site.

Error Code
500 - Internal Server Error
This is a temporary server error.
Please try to reload the webpage later.
If you are the webmaster of this site please log in to Cpanel and check the Error Logs. You will find the exact reason for this error there.

Common reasons for this error are:

Incorrect file/directory permissions: Above 755.
In order files to be processed by the webserver, their permissions have to be equal or below 755. You can update file permissions with a FTP client or through cPanel's File Manager.

Incorrect Apache directives inside .htaccess file.
Make sure you have not specified unsupported directives inside the local .htaccess file. Such include PHP settings and Apache module settings.

Code I added
<!-- Google Code for Website Sale Conversion Page -->
<script type="text/javascript">
/* <![CDATA[ */
var google_conversion_id = 1013936117;
var google_conversion_language = "en";
var google_conversion_format = "3";
var google_conversion_color = "ffffff";
var google_conversion_label = "1m69CK3tx14Q9d-94wM";
var google_remarketing_only = false;
/* ]]> */
</script>
<script type="text/javascript" src="//www.googleadservices.com/pagead/conversion.js">
</script>
<noscript>
<div style="display:inline;">
<img height="1" width="1" style="border-style:none;" alt="" src="//www.googleadservices.com/pagead/conversion/1013936117/?label=1m69CK3tx14Q9d-94wM&amp;guid=ON&amp;script=0"/>
</div>
</noscript>

[admin]

hello andy, i had released a few updates to the OPC's Tracking feature recently and i believe this problem is already fixed. I've sent you the update via skype, let me know how it goes.

In general, you don't need to enter your "code" into the OPC's code input. You only need to enable the "Google Adwords Tracking" within the OPC Extensions tab and configure your params.

best regards, stan