A Soho landlord's plan to remove the external fire escapes from two landmarked buildings at 69 and 71-73 Greene Street has the tenants of those buildings nervous, possibly setting the stage for a Landmarks Preservation Commission battle when the plans are presented next week. The architect, Joseph Pell Lombardi , claims that the removal of the fire escapes "actually is a positive thing in terms of fire safety, because while we're taking down the fire escapes, we are installing a deluge system of sprinklers."