Micro Seiki RX 5000

You do not seem very 'mechanically minded'. Leave the TT alone if it is working!
If you screw it up.. you will be very sorry! bending the spindle is your biggest worry, bending the bearing shaft another.
My advice LEAVE IT ALONE!!!!
The old wisdom comes to mind: "If it isn't broken, don't fix it"

I believe this is a sealed oil bearing but I may be mistaken. Why do you think it needs service. If this has a pump and the platter wouldn't turn, it is probably a RX5000fv. If so do not try to turn the platter without the pump on and floating the platter.

Or maybe the pump is missing. If it will not turn or has a FV designation, don't force it!

The spindle should unscrew by hand. It may be frozen from age. Take it off without burring or scratching by using a cloth and light plier work. Lube it when putting back on.

I concur with Elizabeth but If I were you, I'd take the whole thing to a high end turntable specialist to bring back to full glory. I've been looking for one of these for a while. Good luck.