Precision M6500 - Change speaker board?

Got an old Precision M6500 dual core with a blown speaker. Can get a replacment board off ebay, but not sure how difficult it is to change. I lifted up the top plate and can see the speaker board, but don't see any screws on top to remove to get the board out.

Has anyone changed the speaker board and how hard is it.

Can't find anything on the net to help me.