Use these instructions (see Figure 4 and associated text explanation): http://www.computer-darkroom.com/lr2_find_folder/find-folder.htm
This allows Lightroom to connect to the photos on the different drive. XMP is irrelevant here. Do not do any importing.
You need to move/copy the images to a different hard drive following the same hierarchy.
Once done, move the current catalog as well and open it in Lightroom.
Please disconnect the original hard drive.
You will get "?" on the folders or "!" on the files as Lightroom will not be able to find the folders and files, please follow the below link.
Let me know if this helps.
No need to move or copy anything.
Catalog file is not on the defective drive, so it doesn't need to move.
Backups of photos are not on the defective drive, so they don't need to move.
Thank you for your response. I have it working now. ADubin