alter query to partition a non-partitioned table in oracle 9i

could anybody give a example to alter a non-partitioned table for adding partition. example: i have created a table with struture :

CREATE TABLE SALES_RANGE_NEW (salesman_id NUMBER(5), salesman_name VARCHAR2(30), sales_amount NUMBER(10), sales_date DATE);

now i want to add range partition in it on column sales_date as:

PARTITION sales_jan2000 VALUES LESS THAN(TO_DATE('02/01/2011','DD/MM/YYYY')),

PARTITION sales_feb2000 VALUES LESS THAN(TO_DATE('03/01/2011','DD/MM/YYYY')),

PARTITION sales_mar2000 VALUES LESS THAN(TO_DATE('04/01/2011','DD/MM/YYYY')),

PARTITION sales_apr2000 VALUES LESS THAN(TO_DATE('05/01/2011','DD/MM/YYYY'