Figuring it out by getting stuck in and having a go is the best way I think. Sometimes there are casualties, at least gaskets are not overly expensive!
I have the luxury of a hydraulic press to help, but the bearings were not overly tight, and with a suitably sized driver (e.g. old sockets or other bearing races as you mentioned) they should tap in with a hammer just fine. If you do it the way I did, you can fit the outer bearing to the outer hub first, make sure it's nicely seated, drop in the spacer then fit the inner bearing. That way you're only dealing with one interference fit at a time.
Not to be patronising, but make sure if you drive bearings in that you apply force to the race that is being fitted to the hub/axle. In terms of case of fitting the bearing to the hub you want to apply force to the outside race as it is being gripped by the hub. If you applied hammer blows to the inside race, the shock of those blows would have to be transferred through the bearing surfaces and the ball bearings themselves and it's quite likely you'll deform one or other of them and the bearing will be ruined.
I have the luxury of a hydraulic press to help, but the bearings were not overly tight, and with a suitably sized driver (e.g. old sockets or other bearing races as you mentioned) they should tap in with a hammer just fine. If you do it the way I did, you can fit the outer bearing to the outer hub first, make sure it's nicely seated, drop in the spacer then fit the inner bearing. That way you're only dealing with one interference fit at a time.
Not to be patronising, but make sure if you drive bearings in that you apply force to the race that is being fitted to the hub/axle. In terms of case of fitting the bearing to the hub you want to apply force to the outside race as it is being gripped by the hub. If you applied hammer blows to the inside race, the shock of those blows would have to be transferred through the bearing surfaces and the ball bearings themselves and it's quite likely you'll deform one or other of them and the bearing will be ruined.