I did my front wheel bearings (all four) a couple of months ago for the first time. Still not sure I got the preload right but it works for now.

What I did for the seals was support the hub on a couple of blocks of wood, leaving space underneath the seal, then used a blunt object (1/2" extension, although a large brass drift or block of hard wood might work) + hammer to pound out the inner bearing and the seal from the other end of the hub. If you work carefully, go around the circumference of the bearing, and use moderate, but firm taps with the hammer, you shouldn't damage the bearing. Just walk the seal out a little bit at a time.

The bearing races are made from hardened steel, so it's unlikely they will be messed up, unless you use a similarly hard piece of steel and only hit it in one spot the whole time.