If you want the changed information to be on the same line of the same page that it was on originally, that is not going to happen, at least not in Word.

Be aware of the Track Changes feature in Word. If you turn this feature on and then make your changes backwards (last change made first) you should be able to easily find what is to be changed and make the change. Tell Word to not display changes in balloons but in-line, at least for now.