Recently I had to replace wheel bearings on my Bandit 400 because old ones were quite noisy. I postponed this action as much as I could because I had a fear of bearing removal process. Now I know it is not a big problem even without factory tools.
Workshop manual states you need bearing removal tool which is essentially an insert which will lock itself up in bearing hole so you have something you can hit with wedge bar. This tool is not necessary. You can do this job even with bar itself if it has edges sharp enough. The problem here is that there's a spacer tube inserted between bearings which makes aligning bar against inner edge of bearing complicated.
It is possible to hit inner edge of left bearing because the inner holes in both wheels are assymethrical. So you can push spacer to the side revealing small part of bearing inner edge. You then need sharp bar to prevent it from slipping into bearing hole. After several hits by hammer bearing should slide like milimeter or two out giving the spacer enough play that you will be able to hit bearing properly. After a few more hits bearing will fall out of wheel. The opposite side bearing is an easy pie as spacer tube will usually fall out with bearing.
New bearings can be installed using wheel shaft, old bearings and some spacers. Just put washer, old bearing, then new bearing, spacer tube onto wheel shaft, insert it into wheel and then add another new bearing, old bearing and some stuff to act as spacer so you will be able to push bearings into wheel by shaft nut. In some cases it may happen that old bearings will remain locked in the will together with new ones but gentle hit with small hammer or flat blade screwdriver can help you to get it out. It is not held in very firmly.
Original bearings are 2x 6302Z in front wheel and 1x 6303 RS + 1x 6303Z in rear wheel. Rubber sealing is used on left side under pulley. I opted for 2RS variant for all four bearings. At least in rear wheel the selection of half-opened bearings is not wise as dust and mud can find it's way into wheel hub and bearing grease changing it to abrasive paste. Front wheel has center hub fully closed so the risk of introducing dust is lower but bearings have additional protection of speedometer gear on left and steel spacer on right.
I wasn't able to find the answer for question if wheel bearings should be of standard clearance or C3 bearings for higher loads should be used. I've heard opinions that I should fit standard bearings as this is not a crank and I've also heard opinions that I have to use C3 bearings because alternators do use them too. I opted for C3 bearings because these generics are so cheap even in highest quality and the process of bearing replacement is so easy I don't mind changing them next season.