Once you pull it down to deal with it makes sure you redo all the layers. With spray adhesive. I have used the super 90 it works good, supper 77 is not good for bonding to the roof. Make sure you follow the directions on the can and don't be cheep spray it on good and fairly thick. I can guarantee you only want to do this once. Might be worth a call to Scamp
and get what they use but I am sure they are spraying it with a spray gun. Stayed up for 30 years so I guess that's pretty good.