Best approach to refresh patch files

Hi, So I have a question about the best approach and steps to take when we need to update our patch file directory and lower the number of patch files it is holding. Let me explain the situation.

We've been using the program for several months now, and we patch at least 2-3 times a month, so we have about 35 or so patch files now. The earlier patches we had were large (one was 1Gb), so when we move from version to version, since the program takes all previous patch files and just 'adds the new ones' to the next patch, all our patch files from version 1.0 to 7.12 (current) are over 1Gb in size, then add in all the other version to version files, and our patch directory is holding near 40Gb of files or so.

What we need to do is 'reset' everyone so that we are back down to the 'newest' patch file (a smaller one). For new users, this is not an issue, since the Installer program we use includes all the latest patch files, and the latest client.wyc and wyUpdate.exe files. But the area I see for potential problems is with existing users. I can't just remove all the patch files and start with a new one, since that will likely make the the updater error out.

So what is the best method to 'reset' all our existing user's update files and then we can delete all these huge patch files from our directory?

Thanks!Bill