Modifying custom pipeline component, no effect

Hi

 I wrote a custom pipeline component, installed in gac, created and deploy a custom pipeline and depolyed. Everything works fine. Then I go back and change the custom pipeline component – only delete several lines of code in the execute method, no signature changes. I tried everything, uninstall the custom dll and reinstall it into GAC, overwrite the copy under Biztalk\Pipelin Component folder, undeploy the custom pipeline project, redeploy, restart the biztalk service group, the change just does not take effect.

The code in Execute method:

//XmlDocument doc = new XmlDocument();

//doc.Load(pInMsg.BodyPart.Data);

//doc.Save("c:\\abc.xml");

"what is this name?");

The first time, the xmldocument save code was not comment out.

Would you please let me know the proper steps that I have to take after I make a change in the custom pipeline component?