How to download ear file of my WD java application from portal server

Hi,

I have created one WD java application and i deployed that application into portal using my NWDS or SDM.

I want to know suppose in future my NWDS got corrupted or for some reason my source code get lost from my local machine, and i want to retrieve back my deployed webdynpro ear file from portal server, how can i get back my deployed wd ear file or in other word how can i download my wd java ear file from portal server.

please let me know wat tool or procedure id there to do this ?

regarsd

Rahul