relink several links that have unlinked

Hopefully, by clicking on one of them, then clicking on the Relink button at the bottom of the Links panel and navigating your way to where the file is located on your system. Then double-click on it.

If you're lucky, and the rest of the unlinked files are stored in the same folder, InDesign will ask if you want to relink the rest of them. Click the Relink button and it'll be the end of it.

If not, it'll be lather-rinse-repeat for the rest of them with the process outlined in the first paragraph.

Hope this helps,

Randy