I have a client with well over a thousand documents all created with a letterhead in MS Word. We'll call it 'Letterhead A'. They have recently changed offices and now have a new letterhead: 'Letterhead B'. They need to be able to take these documents and easily change the letterhead on them as they use them. i.e. Open the old document and somehow update the letterhead to the new letterhead and save it.
Any ideas on how we could even attempt this would be much appreciated.