Installing bearings

When bearings and shafts are properly matched, it might seem like bearing does not fit. Well, the bearing is supposed to fit super tightly while being strictly co-axial with the shaft. This is to prevent any slippage and wobbling. In order for it to fit, you need to align bearing with the shaft and then steadily apply the pressure. This is very hard to achieve by hand or by using a hammer. You should use some sort of press or vise. Here is one way to do it:

When removing the bearing, ideally, you should use some sort of press or bearing puller to apply a steady pull equally distributed to sides of a bearing. If using hammer, make sure you provide a good support on all sides: