Internal mast sheave replacement – how to remove

Hi everyone,
I’m looking for advice on how to replace this internal sheave inside the mast of my sailboat. Most setups I’ve seen have the sheave axle and plates accessible from the outside, but in this case, it seems to be recessed and only held by two screws – one above and one below the sheave opening.

     •     Has anyone worked with a similar system?
     •     Is it likely that removing just those two screws will allow me to extract the sheave and replace it?
     •     Also, where would be a good place to source this kind of sheave or housing?

Appreciate any insight or photos if you’ve done something similar!