Mass Deletion of Maintenance Plan and maintenance Items

Dear Experts

Is there any way to delete(Flush out) all the Maintenance Plan and maintenance items from the system?

There are around 450 Plans and 1200+ Items. While running the LSMW, due to some error, extra 521 items got created. So I want to know, if there is any way to flush out all the data (Plan and items) from the system, so that I can create them again.

Or else suggest me an alternate way of correcting this