You can open this form directly, by pressing Layouter.BitmapAndLinks icon 
then select update links tab.
Within this tab, you can see all of externally linked bitmaps which need to be updated in active document. This searching is limited to the chosen range of pages. On the right side is the text box displaying information about the chosen file from the list
If you tick check also embedded bitmaps option - embedded (not externally linked) bitmaps which sources had been changed will also be included in the list of files. It affects only bitmaps which had been imported by Krasbit Layouter import macros, and contains some extra information about the source file.
You can choose a desired range (current page, pages FROM - TO, all) in the Range frame placed at the bottom.
Usage of buttons:
refresh list
This button refreshes the list of files for active document, range and scope.
show selected item on the workspace
This button display the relevant page and makes bitmap selected for the chosen item. You can use it to quickly localize on the stage items that has been displayed in the list.
update link for selected item
This button updates link for selected item on the list. But if the bitmap is embedded, then new version of image is placed on the stage.
update links of all external bitmaps in chosen range
This button updates link for all items on the list. But if the bitmap is embedded, then new version of image is placed on the stage.
Keep aspect ratio option
If this checkbox is ticked then updated bitmaps will get the aspect ratio from modified source file. Otherwise, updated bitmaps will remains previous aspect ratio, which may results in disproportion if the source file had been changed aspect ratio.
export list of all bitmaps
Press this button to export current list of bitmaps and related information to the text file. The file will be placed in the folder where the active document file exists.
RELATED SHORTCUT ICONS
update selected bitmap
macro: Layouter.updateLink
This macro updates a link for the selected bitmap on the stage (if externally linked). If bitmap is embedded, then new version of image is placed on the stage. It affects only bitmaps which had been imported by Krasbit Layouter import macros, and contains some extra information about the source file.