Identifing Duplicate Activities.

I am not sure how it happened, but after importing mulitple xer into my master schedule I have hundreds of duplicate actvities. I need to identify or delete these activities. Any suggestions would be helpfull, going thru the schedule day by day could take awhile. I was hoping that a gobal change or doing a a sort could do it faster. but I just can't wrap my brain around this one.

any help would be appreciated

thanks for your time