Two people is also a good idea, get someone to to hold a little screwdriver tight, whilst you do all the turning etc - hate those things and have had my share of grief with them.
Came across a new one today, on the Hamilton, in the middle of the H links is a little tube and the pin needs to go through it - I broke my cheap e-bay bought tool doing it, but got there in the end.
God bless Steinhart with their simple one sided screw pins - heaven.