you cannot re-glue the headliner, you will have to take the car to an upholstery shop and install a new headliner, for a top job you can expect to pay about $450-$500 and you will have many years.
PS: when I had to replace the headliner on my 987CS, I paid a premium charge (not too much extra) to use alcantara instead of regular headliner material, and the ceiling came out fantastic! Way better than the OEM that came with the car.you cannot re-glue the headliner, you will have to take the car to an upholstery shop and install a new headliner, for a top job you can expect to pay about $450-$500 and you will have many years.