Sir, you should move to the same Hon'ble Court, which passed the decree in your favour. You may file for execution of decree by making the Legal Representatives of your deceased father as defendants citing reference of the previous decree passed. This should serve your purpose. Please note that it would be an execution, so the objections of the legal heirs would not matter as it is not a trial rather an execution. Had they have any objection, they would have opposed the same during the trial back in 2001.
Good luck!