The he goes off for sa'i between Safa and Marwah (two small hills). And when he reaches the foot of Safa he reads Allah's saying: Innas-safa wal marwata min sha'a'irillahi faman hajjal baita ‘awi`tamara fala janaha ‘alaihi an yattawwafa bihima wa man tatawwa'a khiran fa'innallaha shakirun ‘alimun
Behold! Safa and Marwah are among the Symbols of Allah. So if those who visit the House in the Season or at other times should compass them round, it is no sin in them, and if any one obeys his own impulse to good, be sure that Allah is He Who recognizes and knows.) and says: Nabda'u bima bada'allahu bihi (We begin with what Allah began with.
[Noble Quran 2:158]
Then he begins with as-Safa - climbing upon it until he can see the Ka'bah. 
Then he faces the Ka'bah - and makes tawhid of Allah and takbir, saying:  Allahu akbar allahu akbar allahu akbar - laa illaha illallahu wahdahu laa sharikalahu - lahul mul ku wa lahul hamdu - yuhiu wa yumitu wa huwa ‘ala kulli shai'in qadeer - laa ilaha illallahu wahdahu laa shareekalahu - anjaza wa'dahu wa nasara ‘ abdahu wa hazamal ahzaba wahdahu Saying that three times and making du'a after each time. 
Then he descends for sa'i between Safa and Marwah, as the prophet of Allah said : Make sa'i as Allah has prescribed sa'i for you. 
So he walks till he reaches the green sign-post - on the right and left - then runs quickly till he reaches the next sign-post. And this place was in the time of the Prophet a dried river bed covered with small stones, and the Prophet said:  (The river bed is not crossed except with vigour.) Then he walks up to Marwah and ascends it and does upon it as he did upon as-Safa - facing the Qiblah, saying takbir and tahlil and making du'a  and that forms one complete circuit.
Then he returns till he ascends as-Safa - walking in the place for walking, and running in the place for running - and that is a second circuit.
Then he returns to Marwah - and so on till he completes seven circuits finishing upon Marwah.
And it is permissible for him to go between Safa and Marwah While riding. However the Prophet preferred to walk. 
And if he makes du'a in sa'i, saying : Rabbighfir warham innaka antal a'azzul akram (O lord forgive and have mercy, verily You are the Most Mighty, Most Noble) then there is no harm as it is authentically reported from a group of the Salaf. 
Then when he finishes from the seventh circuit upon al-Marwah he shortens the hair of his head  thus ending the ‘Umrah - and everything that became forbidden to him upon entering ihram now becomes permissible again - and he remains in the state of hill (being out of ihram) until Yawm at-Tarwiyah (8th Dhul-Hijjah).
And he who made ihram not intending to make ‘Umrah before the Hajj - and not having brought the hady (sacrificial animal) from outside sacred precincts then should also leave the state of ihram in obedience to the Prophet's order and in avoidance of his anger. Those, however, who have bought the sacrificial animal with them remain in ihram and do not leave that state until after the stoning on the Day of Sacrifice (Yawm an-Nahr) (10th Dhul-Hijjah).