You won't know this until you open things up.
When I had my part tire roof repair business we sometimes worked the membrane loose by pulling gently up and using wooden paint sticks shaped like a putty knife and plastic putty knives too work the membrane loose. Most of the time the membrane simply came loose with a bit of tugging up and back.
I will say every unit was different in terms of removal.
As I mentioned google and you tube can give you ideas on this type work.
Eternabond and other type tapes aren't permanent but will last for many years if the job was done properly. If you go that way be sure and use a self leveling sealant around the edges like the pros. Lots of you tubes for sealing tape.