Hi
Get in touch with your local Snap On tool dealer and buy one of these in the appropriate size:
https://store.snapon.com/MultiSpline-Ex ... 75457.aspx
I have never seen or had one of these break - OK it will probably cost around a tenner but what price confidence?
Warming is a must in my opinion, off in an oven or in situ with a propane torch.
Regards Mick