If I recall correctly the twin lenses are easy to clean, internally. However, if, as Ian offers, it is a result of the cementing failing, I would not know what to do. Sorry, but chances are the seller knew of this and hoped to catch someone offguard.
But, if the haze is merely the result of air imparting its pollutants upon the inner glass (remember, element surfaces between the aperture are NOT airtight) you might simply be able to unscrew the front. I think on the old style lenses this was done easily. The worst that can happen is that you would need a spanner wrench (I use a pointed, old pair of shears for this!!!) and carefully unscrew the ring either on front or rear. - David Lyga