iPod Dreaded Exclamation Mark

I have had to change computers a few times over the last several months and seem to have combined my old itunes library file with a new scan of my backed up music. So, i now every song in my library is duplicated, but one has the exclamation mark next to it . I know why and how it happened. The good news is that i know i have all my music from the back up file. the bad news is, to clean it up, I would have to go song by song to delete the dead link songs.

I'm looking for any suggestions on how to speed up the process as I have over 60GB of music. It would be a 5 minute fix if i could simply sort on that first column and select all exclamation mark files and delete. Also, i prefer not to add on third party software to itunes because I've had bad luck with that in the past.

Thanks in advance for your suggestions!

Won't i lose all my playlists though? I know it sounds silly, but i have dozens of playlists that have sentimental value and it would take me hours to recreate those.

thanks for the fast reply!