Quick question. I can't change gear with a shifter, I suppose the gear cable might be an explanation. I don't have skills to repair that myself. It's stuck in high gear and I just want to lower it. Is there a possiblity to change gear manually? If yes, how?
Very generally speaking, the hub is operated by a cable that pulls on a rod sticking out of the center of the hub. If you can figure out what adjustment makes that rod go in and out you can change the gear (assuming it's not the hub itself that is frozen and not allowing a gear change). But you need to get the adjustment right, since, for some hub styles, being "between" gears is bad.