I would first try the "Fonz" method by tapping on the starter while someone else attempts to crank it. If it didn't have any trouble before you parked it for a month, then it should free-up just fine with the afformentioned method. Taking it apart would likely fix it and it really is the right way, but if you want a quick fix my method should work. Please let us know what comes of it.
Have fun, adam Bush