I did not know if it was possible, but I could not imagine it was not. With help of the docs
http://docs.jboss.com/jbpm/v3/userguide/taskmanagement.html paragraph 9.2
and the javadoc mentioned in the previous post, I found it in less then 5 minutes. You could have done this yourself I think if you just learn the basics of jbpm
Very much thanks for the reply , yaa i got the the reassign process as you mentioned in the javadoc reference.