Environmental Protection

A new service was launched and new pamphlets with information on the new service were printed. Shall we:
(1) replace the old pamphlets with the new ones, and send the former to recycling company?
or (2) Since the old one does not contain wrong information, consume all of them first before using the new ones, for the sake of environmental protection?

My colleague chose (1) but the Head chose (2)...........I will choose (3), which is (2) plus adding to the old pamphlet a sticker with information on the new service.