one think that I found out is my tool chest is full of different bearing presses... sockets

I use different sockets that will just fit around the edge of a race... or what ever I am pressing out... and then hammer on that....

or try the following... heat the outside in an oven.... and put the bearing in the freezer... the shinkage and expansion difference will allow the bearing to just slip in/on with no effort...

work quick cause things heat and cool quickly and you need to get them in place before it gets stuck...

my .0002cents worth

You could run a piece of threaded rod through the center and tighten the nuts on each end to pull everything together. Use big washers or other spacers to make sure that everything is pushing in the right place. (The socket recommendation above can be quite handy.)

Some hubs are quite tight - you really need a press. A socket and threaded rod as someone suggested will
often work, but you can also remove the hub and visit someone w/ a press - most auto machine shops can
do this for you pretty cheaply.

i'm not clear as to your question.

to get the bearings into the rim, doesn't make sense. if you mean the bearing "race" into the hub, then it helps to taper the lip of the race to help start the race into the wheel hub. make double sure both hub and race are squeaky clean.

as others have already said, freeze the bearing race and heat the hub with anything. if you clean off all the grease from the hub you can use an oven, a blow torch, a propane plumbers torch, mapp gas, letting it sit in the sun for an hour or more. it really helps. good luck.