I've tried a toothpick with bearing grease but you can't really get very much past that seam. maybe a little bit of oil can be dropped in, but it's really a poor design and you can almost count on it failing anytime after abt 750-1000 miles tho some have said they got 2000mi.
it's press fitted at the factory but if it's shot, it'll come apart bcs some of the balls get flats on them. I think my new clutch assembly was $23 when the original went @ 850miles