all cost of dismantling and reassembling subcontractor's furnished equipment, option equipment, and other portions of the work shall be paid by subcontractor. When it is necessary to dismantle piping, ducts, machinery, or equipment not furnished by subcontractor in order to obtain access to subcontractor's equipment, option equipment, or other portions of the work, the reasonable costs of all such dismantling and reassembly will be paid by main contractor.