Working on L2C4 with old server files. This is kind useless now.
(But if you are playing on L2C4 on L2Off files w/o FREE patch for this dupe, you will be able to do this)
There is a video tutorial for this:
http://rapidshare.com/files/77072737/dupe.wmv
It is easy to get red handed.
Regards,
Lx