you are going to want to sync your folders, basically have lightroom go back into your hard disk and just sync it up with the changes you have now. the catalogues will then reflect exactly what you have now on your hard disk if you do it right!
to do so:
When you synchronize folders, you have the option of adding files that have been added to the folder but not imported into the catalog, removing files that have been deleted, and scanning for metadata updates. The photo files in the folder and all subfolders can be synchronized. You can determine which folders, subfolders, and files are imported.
- In the Folders panel, select the folder you want to synchronize.
- Choose Library > Synchronize Folder.
- In the Synchronize Folder dialog box, do any of the following:
- To import photos that appear in the folders but have not been imported in the catalog, select Import New Photos. If you select Show Import Dialog Before Importing, you can specify which folders and photos are imported.
- To remove photos that have been deleted from the folder but not from the catalog, select Remove Missing Photos From Catalog. If this option is dimmed, no files are missing. (You can choose Show Missing Photos to display the photos in Grid view.)
- To scan for any metadata changes made to the files in another application, choose Scan For Metadata Updates.
- Click Synchronize.
- If the Import Photos dialog box opens, specify the folders and files you want to import, and then click Import.