Service Confirmation order update for spare parts and labour hours

Hi,

I have created service confirmation with crm_order_maintain, but i want to update Start of work date and end of work date, duration hours and Spare parts like Material and Unit of Measure,

i try to read the above created order with crm_order_read by passing APPOINTMENT as requested object to get the Appointment table to see the how dates are filled.

But when i try to update the dates with APPT_TYPE = SRVC_ACTUAL, it is not updating,

same way i want to update the spare part information like Material and Unit of Measure.

Please help me some tips. How to approach.

Thanks,

RamNReddy