Reverting the Global Schedulable and IScheduled classes. We cannot push upgrade changes to the first one if there are jobs scheduled, and we cannot change the signature of the latter one (because it's global). We'll created replacements for them instead.
Uninstall script should abort any existing NPSP scheduled job.
Creating classes to replace UTIL_GlobalSchedulable and UTIL_IScheduled. Using the replacement in the install script and the batch classes to run from the scheduler.
The method in the new interface does not have any arguments.