Slice feature

I have a header which I would like to make some modifications to, the author of the header stated this

If you want to make changes to the header for buttons are anything else you can open the file up in Image Ready and the slice guides that I used should be visible to you. That way you should get an exact slice guide to match how I sliced up the header area

I am not sure how to turn the slice guide on using Image Ready, I have played around but cannot figure how to do it. Any help would be great.

Thanks
SB

I upgraded to Image Ready 7 and now I get this message

Could not read adobe Image Ready specific data because slices were in an unsupported format

I suppose version 7 is too advanced