How to perform Qaza Namaz of life time easily

If someone have missed Salahs in their account. Either one time's or
of many years, they must pray their Qaza as soon as possible. Salah is
a Fard and not forgiven. On the day of judgementSalah will be the
first thing asked about.
For the people who havemany years of missed Salahs. There is a way to
pray them quickly. Following instructions have four exeptions and has
all Fards and Wajibs for a complete Salat. Please pray your Qaza as
soon as possible. Even of you could pray one days Qaza Salahs every
day which are only 20 rakahs(3 wajib witr), please do it. It only
takes few mins to perform 20 rakahs according to the following
instructions.
1) In Ruku and Sajdah instead of reciting"Subhaana Rabbiyal Azeem" and
"Subhaana Rabbiyal A'la" three times, say it only once. But make sure
do not leave Ruku poster untill the Meem (M) of Azeem has been said
properly. Similarly do not leave the posture of Sajdah until Ala has
been said completely. Just make sure to say these Tasbeehaat properly
anddo not rush.
2) In third and four Rakah of Fard Salah instead of reciting the whole
Soorah Fatiha say,"Subhan Allah" three times and go to Ruku, . Make
sure "Subhan Allah" has been recited three times properly, do not
rush. This exeption isonly for Fard. In third rakah of Witr it's a
must to recite full Soorah Fatiha followed by at least three ayahs of
Quran or a soorah (as weusually do in first and second rakah).
3) In last Qaidah (when we sit for Attahyyat) before Salam, after
Attahyyat instead of full Durood and Dua just say,"Allah Humma Salle
Ala Sayedena Mohammad Wa Aalihi", then finish the Salat with Salam.
Dua is not a must here.
4) In Witr, instead of full Dua-e-Qunoot just say"Rabbigh Fir Lee" one
or three times.
(Fatawa Rizvia, Part 3, Page 622)