Merge subscriber records

Is there a way of merging subscriber records? Context: I have a subscriber who has subscribed to a number of lists using different e-mail addresses. One e-mail address is no longer valid. I want to merge the history as well as the data for the two individual subscriber records in to the correct e-mail address. How do I go about doing that, so that the two records become one?

I was just wondering if anyway of merging individual subscriber records was available, yet? When I try to manually change the subscriber e-mail address I just get the (half expected) message that the subscriber e-mail already exists.