expanding a column defined as varchar2(250 char)

Oracle 11.2.0.4

I have a requirement to expand a column from 250 Unicode characters to 1000 Unicode characters; the column does contain a value.

Here is the table definition:

[Code]

Columns
NAME                            DATA TYPE             NULL  DEFAULT    COMMENTS
*CONTRACT_NBR                   NUMBER                No                  
VEHICLE_DISPOSITION_NBR        NUMBER                No    0             
QUANTITY_ENTRY_NBR             NUMBER                No    0             
SETTLEMENT_NBR                 NUMBER                No    0             
TRADE_BLOTTER_NBR              NUMBER                No    0             
VEHICLE_STORAGE_NBR            NUMBER                No    0             
TEMPORARY_STORAGE_NBR          NUMBER                No    0             
BATCH_NBR                      NUMBER                No    0             
ADVANCE_NBR                    NUMBER                No    0             
MAX_DPR_DATE                   DATE                  Yes                 
DPR_TRANSACTION_NBR            NUMBER                No    0             
DEBIT_CREDIT_NBR               NUMBER                No    0             
WASH_NBR                       NUMBER                No    0             
ACCRUAL_NBR                    NUMBER                No    0             
ACCRUAL_INVOICE_NBR            NUMBER                No    0