I am starting a new thread that hopefully can be searched out if someone is missing their journal brasses and has to do something to get by. I can post details on one particular size but maybe others can add notes on new sizes.
First, suggested tools:
2 50t bottle jacks
several blocks of various cribbing for the jacks
small thin long hooks, pliers, etc, you'll need to reach into the box to remove, replace, position the liners and bearings, and you should absolutely never put your hand in there, unless you're just not too worried about leaving with the same amount of fingers you arrived with. I suspect the correct tools are best, but I got by with large pliers and long screwdrivers.
A large tamper bar/prybar.
some tow straps.
a knee pad!
In my case, the trucks were 'out of square' with some journal boxes several inches out of place laterally. This has to be forced back into place to get things to fit.
You may want to remove the packing from under the journal first. I did not, they seemed to compress and rebound fine. I suspected if I took mine out, they may disintegrate and then i'd have nothing.
Place the bottle jack under the journal box and jack it up. In some cases, you may need to jack up the opposite side a little, just so your side will drop down.
My bearings were 4 1/4 x 8 . A standard hardware store 2x4 (real size 1.5x3.5) was the perfect raw material. Cut the 2x4 into 8 inch blanks. On what will be the 'top', chamfer the long edges to a 45 degree angle, about 3/4 an inch material removed. You may want to also chamfer the top of the short end to help clear the liner. Then you need one last step and you could do it a couple ways. The 2x4 is a bit thick. Quick and dirty you could cut them down to about 1 1/4 thick, or the other option to radius the bottom for the journal to make it a bit thinner. My two thoughts were to mill the bottom with a table saw, or compress them with a piece of pipe in a hydraulic press. Mine were all a bit thick and I had to hammer the liner to get it to slide into place. This will get you a ready to use wooden bearing. Good luck!