Lawrie, 30, had two stints with the club after joining as an apprentice in 2005 and the hooker went on to win his sole Scotland cap against Samoa last year. A qualified PE teacher, Lawrie said: "I still have the rugby bug and want to coach at as high a level as I'm able."
Cairns, 28, moved to Murrayfield from Currie in 2005 and ends his career with eight Scotland caps at centre. He admitted he was having difficulties coming to terms with the fact his career was over.
"My cruciate ligament injury came at a really bad time, just after I wasn't selected for the 2011 World Cup, and I feel like my prime was taken away from me. As a kid, the one thing I wanted to do was play for Scotland and I lived that dream. I'm really enjoying coaching at the moment and I'm keen to see if that continues as a career option."