Regarding Portugal D2 Visa Portugal

Looking for Step by Step Real Time Portugal D2 visa information
Any one here , please guide about D2 Visa,
Complete Procedure from NIF till Submission.
after submission SEF /AIMA how long it will take to process and after how many days Embassy will return the passport with approved visa.
Anyone who already experienced or who already know the procedure, it would be very much help full for many. Thank you.