Since each bearing has to come from the inside out (and opposite sides even), you need to take a punch that is smaller than the spindle diameter and put it through the bearing's inner race - the pry the internal spacer to the side which exposes the opposite bearing's inner race. Using the punch, you can drive it out using that inner race and it WILL ruin the bearing you are removing. Walking side to side or even in 4 steps around the bearing will get it to come out - holding the hub in a vice is much much easier.
Once the first bearing is out, flip the hub over and drive out the second one in the same fashion. This is much easier as you won't be driving at an angle due to the spacer or the first bearing being in your way - you can hit 'er straight on.
I always take one of the old bearings I just drove out and take it to the grinder - I grind the outer race all the way around so it just drops into the hub - this becomes my new driver for driving in the new bearings - no socket to buy and it's almost an exact fit - as close as you care to grind it. They go in pretty easy this way - but again, I've only done it with a vice.
As for the oven idea, I'm not sure - I've never done it to the hub. I have however used a hotplate to heat up a case half while the crank (with bearing already installed) spent time in the freezer - this makes them go together so much easier. I'd assume if you put the hub in the oven and the bearings in the freezer that they will almost drop right in. - Don't forget the spacer between the bearings.
Also take note to the seals on the hubs - they are of an interesting design and if you aren't paying attention, easy to install backwards. The manual actually does a good job of showing you the proper orientation.
