If it has a ring with 2 indented holes, you can spin this off by spinning it around using a screw driver and light taps of a hammer. You can then remove the gear set but be warned that dozens of tiny ball bearings will then fall all about. Once the gears are off you can use a pipe wrench to remove the remaining part.
THere are instructions on you tube on doing this and if you're careful you can re assemble without damage.