Hi boca,
The sanding pad needs to be removed along with the two post units that hold the pad. Then the screws which secure the housings come out. You should then be able to split the housings. There is a decal on the front of the housings that will need to be split if it has not already been. The housings slide around the bearings and they may give some resistance. If a bearing has seized and melted the housings then you may have quite a time splitting the housings.
Good luck!
-UtahAV
-Mark