Hello Power,
/SAPAPO/MD74 program /SAPAPO/RM60RR20; Forecast adjustment and delete selected forecast.
You can choose Requirements Date for your selection and Option 'Send deletion to ERP' is to be set in the transaction /SAPAPO/MD74.
Please refer 1389633 - The forecast deletion is not sent to R/3.
Then you can delete the forecast orders in APO and R/3 using /SAPAPO/MD74.
Best Regards,
R.Brahmankar