Changing JD 120C fuel filter (and/or can I get a service manual?)

Hello, I am having some trouble changing the fuel filters on a JD 120C. When I drain the filter from the secondary filter it seems to drain forever. At this point I am assuming that the fuel is coming directly from the fuel tank but there is no shut-off valve that I can tell. I have traced the fuel line all the way back to the tank. So, it would seem that if I remove the old fuel filter that all of the fuel is going to gush out all over the place. What's the solution for this? Also, I don't understand how the fuel filters attach to the machine. There is a collar around the filter which is very difficult to remove. Does the collar go over the filter and hold it on? Are there any tricks to removing it (e.g., is it counter-threaded) It would be nice to see a service manual for this machine, does anyone happen to have one? It is a 2003 JD 120C. My email is [email protected] . Thanks!!!! Chris