Answer
(Fatwa: 895/710/B=1431)
First he should offer Fajr salah and then Zuhar. And if he missed too many salah then he should offer only the qaza of fardh salah as much as he can. After offering each time salah he should offer the qaza salah of the same time i.e. after offering Fajr salah he should offer the qaza of Fajr salah, or if he can he should offer qaza of more than one salah, and as much as qaza salah he offers he should note it in a notebook. The intention should be made in this way: I am offering my first missed Fajr salah amongst my all qaza salah, or I am offering my first qaza of Zuhar salah.
Allah (Subhana Wa Ta’ala) knows Best
Darul Ifta,
Darul Uloom Deoband