is this live text on the image itself? or is this a name tag on someone's shirt? do you have an example we can look at?
if you want to change the file name you can do that in windows, F2 and then edit.
if the image has text, then you need to use the TEXT tool and select the text and change it
if the name is in a graphic, you'll have to clone the old one out and put a new one in.
---Mike Savad
MikeSavad.com