Once a bearing becomes notchy, it's done. It means it recieved to much of a side load and the balls in the bearing have dented the race. Only fix for that is to replace the bearings. Concerning greasing bearings, the easiest thing to do is purchase a bearning greaser. They work very well, you can use any grease you prefer and is not a very messy process. Check out Heliproz.com or other online retailers.