Well the stock OS# is 46030008
The CFI bearing # is 29430010 This is the one you want if at all possible. If you are using the unsealed one it will work just won't last any where near as long.
As far as changing the bearing it is the same as replacing any typical OS bearing.
The one big difference is the piston ring. it has to be lined up with the pin in the ring groove otherwise the ring will not compress enough to put the sleeve over the piston.
Leave the hammer in the toolbox. if you have it lined up correct the sleeve will smoothly go over it. It's a PIA but after two minutes you should have it.
As far as the needle valve go on Tower's website Look for the parts for the OS140RX and they show the two different needles. should be able to tell which one you have by the pictures.

One other thing the key for the prop washer only goes in one way the flat side to the engine.