So you need to find where those files reside on your disk and point PP to them. For example - do a search for JNSN1089.mp4. Once you find where they are stored, close the project. The easiest way to relink is to just move the files so they reside in a folder that sits underneath the project file. Then when you relauch the project PP automatically scans folders that reside in the project folder and should automatically relink. If it doesn't you need to use the relink files option - highlight a missing clip in the bin and choose Link media, then navigate to the folder with the missing media. Usually, if all the missing media is in one folder it will relink the lot without having to individually select each file.