I need to remove a Y Axis from a VMC, and i do not know how motor coupling comes apart.

The machine is a Vulcan which is a rebranded Kasahara

Here are some pictures of the motor coupling

Attachment 376976

Attachment 376978

Attachment 376980

You can see a collar that is loose, that is just a collar... dont know what it does,

I also tried to remove the other set of nuts and they just spin...

I cant believe that it is this hard to replace a servo?

Any Suggestions?