Software Deployment

What are people doing for the following scenario... We are currently bringing down Office in our XP image and now there are some template changes that need to be brought down to theses installations that are out there from our current image and updated in any new installs of Office. I have updated the transform file we use for installation moving forward but how can I get existing installations to repair the changes on machines that have the old version of the files and then make sure if any users go to ADD/REMOVE programs and do a repair that these new changes will be part of the repair. Any guidance would be greatly appreciated.

Thanks!!!