Any suggestions on how can I make those changes in one go?

Scan the pages of magazines and upload them at www.onlinedocumentconversion.com download editable version within minutes Once you have editable version you can make those changes in word.

I would agree with the other poster but if it is a typo or formating issue you could do a find and replace and quickly get through. Save a copy as something else just in case you break something. lol! Good luck.

This does sound like a major task. The only thing that I can think of is to start at the beginning and keep going until you reach the end. Set yourself a time span allowable for the task. Make yourself comfortable, turn the phone off so you can not be disturbed, gather refreshments and munchies and just go for it. Wish you luck.