Okay, did this tonight and basically if you look at the top of the odometer there's a metal clip, and then a long pin with some gears on it.

remove the metal clip, then remove the long pin with gears on it. turn the odometer numbers to where you want them, and put the pin and gears back on. align the gears so they match the gears on the odometer numbers. then pop the metal clip back on top and you're done!

now my speedo works and i have the right odometer reading

 

glad you fixed it, so odo is moving?

 

To test that it still worked right, I rolled the gear to make the 6th digit on the odometer move as if I was driving, and when it got all the way through coming from 9 back to 0, the 5th digit rolled up by 1 as normal.