The fixed cup is a LH thread. Adjustable cup RH. I don't usually remove the fixed cup. They are in there tight. No reason to unless it needs replacing. I just use a rag on a stick to clean it out. When I replace the spindle, I use grease to hold the bearings onto the spindle and thread it carefully through the fixed cup, hold it and screw in the already loaded adjustable cup with my other hand.