Believe you me, having them drop right in with a couple light taps is far better than trying to do it at room temp. The idea of slamming a hammer on brand new bearings just makes me cringe!
The DS730 I had was a 2001 and I did the bearings this year (so 7 years on stock bearings!)...It took 3 guys a case of beer and about 6-8 hours to get that damn job done. I learned my lesson, and will change out the bearings a little more often
Overall if there are no hiccups (such as a stuck axle...or the carrier gets stuck in the swinger...mine did both) then its really a simple project!