This should be done by turning the face towards the right shoulder so much so that the people behind would be able to see your cheek. As the face is turned to the right, you should say the word: as-salāmu 'alaykum wa raḥmatullah. You should then turn your cheek to the left shoulder and repeat the phrase.

 

السَّلامُ عَلَيْكُمْ وَرَحْمَةُ اللهِ

Assalaamu ‛alaykum wa raḥmatullaah

Peace be upon you and Allah’s mercy

(Sunan Abi Dawud 997, Authenticated by Al Albani as Sahih