How to change page ID to preserve links?

I'm developing a site, and the current site uses the page ID in the permalinks (eg http://ift.tt/1yCPRYX). I am recreating the pages, and would like to make sure I don't break any existing links that people may be using, so I want to change the page ID's on the new site to match the old ones.

I know it can be done. I know that most people that ask this question should be looking at permalinks, etc... and not page ID's, which is not what I'm looking for.

So how do I do it? I've read elsewhere that the only way is to go into the database, what tables do I need to look at?

You get special thanks if you point me to a plugin that does this, or can explain any considerations there would be in creating a plugin to do this.

Thanks!