I have been pondering over the subject of replacing bearings in a motor for a long time!

My questions is:

1. Is it better to replace the bearings by knocking them out or to heat up the crankcase?

2. If you replace the front bearing with a METAL seal bearing do you take out the inside seal or not?

3. If you replace the front bearing with a RUBBER seal bearing do you take out the inside seal or not?