University of edinburgh conditional offer : how to make it uncon.?

Hi everyone!
I received a fex days ago a conditional offer from UoE to study Arabic and Politics that i firmed. This are the conditions i have:

"This offer is made on the basis that we consider your fee status on the relevant date to be EU/EEA fee rate.If our assessment of your fee status subsequently changes, then your application may be reassessed and your offer may be withdrawn...
You must also gain overall IELTS (Academic) score of 6.5 with 5.5 or above in each component, or equivalent.
Please supply a signed copy of your UCAS reference on headed or officially stamped paper."


I'm french and my ielts is above 6.5 and 5.5. So everything should be fine but the problem is that i absolutely don't know to whom i should send it! By mail? By email? To which address?

I hope you'll be able to help me