I used to have details on this, but I've just looked and I seem to have mislaid them. I hope they didn't get junked during the last clear-out ...

Anyway, I can tell you in general terms how to do it. The first step is to get yourself a hex editor - and make sure that the game can read the savegame file after you've edited it. I had one editor that gave me trouble that way.

Second, work out the hex value that corresponds to your characters' ages. Then, open your savegame file with the hex editor, find the characters (easy to do, the names are there in plain text) and hunt around in the figures afterwards for the hex representation of your age. If I'm right about how it's done, (you will have to check this) there will be two values to change for each character. Then change them and see if it works.

One thing however is absolutely vital. ALWAYS, ALWAYS, ALWAYS KEEP A BACKUP SAVEGAME FILE. There is no quicker way of screwing up a file beyond redemption than by getting a hex edit wrong.