To sand bearing surface cut a strip of 180 or 240 grit wet sandpaper 1/2" wide by 8-10 inches long. Put some light oil on the sandpaper and pull back and forth around the shaft. You get about 180 degress of shaft coverage with this arrangement so rotate your pulling position to get the complete shaft circumference sanded. You're not taking off much so the job won't take but a few minutes. Stop-clean-oil bearing and shaft and try it. Keep going till you get a light slide fit. For the cover housing use a small piece of the same sandpaper and just sand around the inside circumference of the housing. Just needs a minute or two of sanding to get this done. Keep trying the bearing fit to achieve a light slide fit. New bearings are SKF 6203 2RS. They are prelubricated and sealed with rubber shields. They replace bearings that have metal shields.