I have a spindle for grinding machine with 20.000 rpm and I want to change the bearings of it. I took them from the trade , 4 pieces new, the number 7005CTYNDULP4, the same number with the spindle. I found out two symbols the "O" and the "V". My question is, how I will placed them? And second, when I received them ,I noticed that , they have a layer of oil for the conservation of them. Before I will placed them to the spindle, I want to put grease. Before I will put grease, could you tell us, if I must clean the layer of oil or not? And if yes, with which material I will cleaned them?