restablishing sync of imovie events on external harddrive to event library

I have 900 Gbytes of imovie events that I imported from all my childrens videos to an External Hardrive that was successfully tied to my event library until I had a a powersurge and my external harddrive had to be replaced with all of the files thankfully restored onto a new external harddrive. Unfortunately now my Event Library on my imac recognizes the new External Harddrive but doesn't see all my events. I can't reimport these files into my computer since the hardrive of the imac will not fit 900GBYTES. Therefor how do I get my I movie Event Library to recognize and be able to use the imovie events on the new external harddrive??? HELP!!!