What BladeRunner said: At least on the 1500 inside the trunk on each side there is a rubber plug pull it out, and under it is a button, push on that while applying pressure to the top out side of the Pannier/ Saddle bag. Unless something is broke inside it should release.
Question ? do you have the Pannier/Saddle bag stuffed full ??. If so that might be what's causing your problem excess pressure against the latches. If so the above should help you out.
From the Northwest Corner
Ron