Sa'i retraces the steps of Hajar as she searched for water for her son Isma'il — seven laps between the hills of Safa and Marwah.
Begin at Safa, facing the Ka'bah, raise your hands and supplicate. Walk to Marwah; men jog between the two green markers. Safa to Marwah is one lap; the seventh ends at Marwah.
Recite the verse of Safa and Marwah on first approaching Safa, then the takbir and tahlil on each mount, followed by your own duas.
لَا إِلَهَ إِلَّا اللَّهُ وَحْدَهُ لَا شَرِيكَ لَهُ، لَهُ الْمُلْكُ وَلَهُ الْحَمْدُ وَهُوَ عَلَى كُلِّ شَيْءٍ قَدِيرٌ
La ilaha illa Allah wahdahu la sharika lah, lahu al-mulku wa lahu al-hamdu wa huwa 'ala kulli shay'in qadir
There is no deity but Allah alone, with no partner. To Him belongs the dominion and all praise, and He is capable of all things.
Sahih Muslim 1218 — said three times on each mount
It is recommended but not required; Sa'i is valid without wudu.
Yes. You may pause, sit or use a wheelchair if needed, then continue from where you stopped.