to get the bearing out take off the sprocket and the clutch using the puller then with a plastic hammer or use a hard wood block tight tapping on the jack shaft form the sprocket side. To drive out the shaft the bearing on the sprocket side once the shaft is out you will still have the remaining bearing to remove it can then be tapped out by using a deep socket from inside the engines housing and light taping to drive the bearing out on the chain sprocket side.
Don't hit the jack shaft on the clutch side unless there is no other way to get the shaft out the center bolt that works the clutch will damage very easily. there is a machined shoulder in the engine housing that the bearing will seat against so these bearing will drive out one way only. you could use a press if you have one but I've found that going easy you can drive the bearing out with out damaging anything to install the bearing it just a reverse of the way you got them out.
I think I show most of this on the engine tear down post in the classic posts.
as for shielded vs sealed you can remove the shield on the inside of the bearing before installing them and get grease into the bearing from the lower clutch cable mount if you take it off you can shoot grease into the hole and get grease to the bearing with out removing the shaft. sealed bearing don't allow you to grease them and the shielded I think are cheaper. Just some useless info.
Norman

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