If the document and images will be kept in the same folder, here's a way to do it that: (a) doesn't require a macro; (b) updates the document just by changing the image in the folder; and (c) keeps the document's file size to a minimum.

1. Press Alt-F9 to toggle Word's field code display 'on'.
2. Press Ctrl-F9 twice to create a pair of nested fields wherever you want the first image to go. They'll look like { { } }.
3. Fill in the fields, so you end up with {INCLUDEPICTURE "{FILENAME \p}/../Image1.png"}. Change the 'png' to whatever extension your image has.
4. Copy the field code from step 3 and paste it to wherever you want the other images to appear, changing the image # in each field to match.
5. Save the document to the folder the images are stored in.
6. Press Alt-F9 to toggle Word's field code display 'off'.
7. Press Ctrl-A, F9 to update the display.

If you change one of the images in the folder, then press Ctrl-A, F9 to update the display, Word will replace the image in the document.
If you copy the document to another folder with its own set of numbered images (same image names & extensions) and press Ctrl-A, F9 to update the display, Word will replace all the images in the document.

Let me know if that suits your needs; otherwise I can write a macro.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]