Yo, Got the freewheel here but it's locked up and will not budge. So I'm wondering if it can be taken apart and serviced so it's usable again? If so, how do I do it? I haven't get the tool yet to take it off the cranks its on at the moment but it looks like I have to take it off the cranks first to do anything else. Are they even worth servicing, or are the pretty much fecked once it's messed up internally? Cheers!