Then lift the top half of the bearing housing straight off; it is free floating-simply lift straight up BUT be careful not to lose the steel ball bearing. It might be sitting on top of the shaft attached to the lower part of the housing but will more than likely be adhered (in a film of oil) in the upper recess of the top half of the bearing housing. Usually a couple of firm raps on a solid table will dislodge it if that is the case but don’t lose it. In the worse case, scenario you may have to use a magnetic screw driver to get it out but be very careful not to scratch the internals of the upper part of the bearing housing.
Once you’ve done that, clean out/clean off all the old oil from both bottom of housing (well and shaft) and upper recess in top half of housing using a lint free cloth.
Then add 2 1/2-3 mm of fresh oil (Mobil 0W-40 or if you want something more exotic-it is better IMO-Audio Origami oil) into the lower well, put a couple of drops of new oil on top of the shaft and place the ball bearing in the middle of the top portion of that shaft in those drops of oil and then replace the upper half of the bearing and put your platter back on and secure it.
If you want a cheap, huge bang for the buck upgrade, order a 7/32" Grade 3 Silicon Nitride ceramic ball from Boca Bearings, wait for it to arrive and use that instead of the steel ball when you do your oil change. Significant improvement in any resolving system for less than $5.
Personally, I prefer to change the oil and ball in my Gyro every 2-3 years. Would never go 5-6 years on an oil change.