just push them both back, use a screwdriver or something, just make sure you don't bur the edge of the piston where it meets the seel, if this fails it is most properly overfilled with oil, which i dought.
if its the same as a ACS put a key/screwdriver/ anything in the hole on the lock ring then back pedal. might be wrong but i use a hope rear hub so it doesn't matter.