Thanks Jim for your reply. I had opened the panel in the storage area to see if there was access to the vac before but where the unit is, under the stairs, there is a plywood wall firmly affixed with wires, plumbing, etc. going through it. I know the vacuum is back there but the wall does not appear to be built for access. Other threads mention taking out inside stairs for access but even after I took all of the screws out of the treads the treads are still firmly attached! Not sure what the screws I took out are holding
Have you ever tried to remove stairs, treads?