Use the SET clause to modify current values at the location pointed to by the cursor.
EXEC SQL UPDATE tablename SET field = 'new_value' ... END-EXEC
tablename is the name of the database table containing the data you want to update.
new_value is the new value you are assigning to that field.
EXEC SQL UPDATE CUSTOMER SET C_INFO = 'Revised' ... END-EXEC
This tells the update program to change the value of C_INFO in the customer table to Revised.