Youtube is definitely your friend, plenty of how-to vids on changing wheel bearings.
Getting the old ones out isn't usually difficult, add some sort of lube (penetrating oil, or at a push WD40 though it isn't the best thing) round the bearing where it fits in the hub. Useful if you heat the hub with a hairdryer or hot air gun, avoid using anything with a flame though. The dust seals usually prise out easily with no damage if you're careful and will refit with finger pressure usually.
The bearings usually go in with one down to the stop, and the other just until it traps