Get them off isnt the issue. the retaining ring will split with the cold
chisel
and hammer.  The bearing itself can be driven off alternating hits side to
side with a hammer and drift.  The problem is getting it on.  The bearing
can be driven on with a piece of black pipe of the correct diameter with a
cap
on one end and a hammer.  But the retaining ring is dicy.  If it isnt
started
perfectly straight, and driven on evenly, it will split.  A good drive shaft
shop
can knock these out right quick, and if its needing a center support, the
U-joints probably arent in the greatest shape ether., so why not have it all
done at a drive shaft shop if ones available and the balance checked as
well?
And make sure you mark the two drive shafts so they go back together the
same way they came apart if you tackle it yourself, or you'll have vibration
and binding issues.

Whitelightning