I can't imagine why someone would use a thread locker on those fasteners, but I have run into stranger things. They also may have ripped the threads out and replaced them with an epoxy and no release coating. This will be a real PITA, but it will work if the screws were set in Lokite or other.... Get a tarp and a soldering gun or iron (a torch won't be confined enough). Heat the fastener as long as you dare and then try to loosen it. If that doesn't work, heat it longer than you think it can stand and try again. You need to trap because any breeze will take all the heat away.
The advantage of this method is that it is non-destructive.
Matt