Universal freewheel remover 1722/2BI | No more struggling with removal of the sprocket on the threaded hubs. This tool, is a huge time saver and makes removal of the sprocket a breeze. #
TheBikeTube
Freewheel Removal and Installation | Park Tool
Park Tool FR-6C Sprocket puller | Drivetrain Tools | BMO Bike Mailorder
sprocket - What do I need to replace my singlespeed freewheel cog? - Bicycles Stack Exchange