I am using the Training Course Website T&Cs, but my users are based outside of the UK. How can I alter 6.1 to reflect this and still have a legally binding document?
Section 6.1 is entirely optional. It is there for you to use just in case you want to apply eligibility criteria. Removing it won't directly affect the validity of any contract under the T&Cs, although of course if you are contracting with persons overseas then elements of their local legal regimes may apply.