Need help renaming some episode titles

I tried to rename the titles of select episodes from Discovery Channel's Ultimate Guide series, since they have the show's title listed in them. The problem is that I cannot seem to remove the show's title from the episode names. The titles listed as "original titles" are the actual titles of the episodes. Help would be appreciated!

https://www.imdb.com/title/tt0415336/?ref_=ttep_ep_1

https://www.imdb.com/title/tt2259338/?ref_=ttrel_ov_bk 

https://www.imdb.com/title/tt12992428/?ref_=ttep_ep_26