How do you cancel subscription to TR Pro?

I joined TR Pro, and duely provided my credit card details.
My annual subscription is coming up for renewel, and I understand that unless I cancel my TR Pro membership, TR will automatically debit my credit card again, which I don’t want them to do.
I can’t for the life of me find out how I cancel my TR PRO membership.

Does anyone know how you do that?

Thanx

Dave