Remove all of the dead parts, leaves and the dead stolon. Place it on top of a pot of dry soil and put it in your unheated garage.
I am not sure you will be able to save this baby. I see that the center of the leaves is looking like it is rotting (last photo)?
Sempervivum will not start from leaf cuttings like many of the tender succulents will.
Jasmine let me know if it responds to the change.
