Simplify the following text for a Grade 14 native English-speaking person.
Original: After the end of the `` Invasion '' at Survivor Series 2001 , the WCW Cruiserweight Championship remained active and was renamed the World Wrestling Federation ( WWF ) Cruiserweight Championship , while the Light Heavyweight Title was retired .
Simplified: Following Survivor Series 2001 , the title was renamed the World Wrestling Federation ( WWF ) Cruiserweight Championship , replacing the WWF Light Heavyweight Championship .