Chain pliers. 0:44 video:
https://www.youtube.com/watch?v=IMZ3fIQ5vo8
Previously:
https://www.homemadetools.net/forum/...163#post134570
https://www.homemadetools.net/forum/...516#post127995
https://www.homemadetools.net/forum/...683#post118481
https://www.homemadetools.net/forum/...4121#post79373