Driver side seat has broken free from positioning rail. How do I fix it?

The pins that you are speaking of are rivets that have torn through the metal that alows the seat to move front to rear on the rail correct? Well if this is the case bolts may not work because the head of the bolts will be in the way of the tract that slides front to rear on the seat adjustment selection. My recomendation is to remove the whole seat and find a local automotive interior repair shop for a quick welding job to reafix the tract in the correct fashion.