Remove the hubs with the outside 6
bolts.
The FSM says, not servicable. well.... not really true...
Look for broken parts , clean it and look again ? , if anything
is broken, they can't be repaired. (unless you get
wrecking yard spare parts)
Remove the inside snap ring ( this will be a harrowing experience
,even
with the 6 snap ring tools that I have in tool box)
Now take it apart and cleang it .
Put it back together with a light coat of marine GP grease ( is use a
1/2" paint brush ).
Than I put back that pesky snap ring.