I currently hold an unconditional offer with Kent university for business law. However through much consideration I have now decided to change my course to sociology and criminology. I'm also sitting 2 exams this summer - so do I wait till summer (when I receive my a level results)? And will they allow me to change courses immediately?
Also, I'm not to familiar with the whole clearing process, for instance when I get my results will my track be updated for the university, or will I have to show certificates to the university to prove I got 'these' results?
I'd email the Undergraduate Office for your relevant Faculty. Assume Sociology and Criminology, and Business Law would be the Social Sciences. Explain that you want to change and your reasons and just ask if it would be at all possible. They should be able to pass your request on to the relevant people to establish if it would be possible BEFORE results, or advise you how you would be best to proceed. I'd say, it's worth a try...
I changed my course in the March before I began, with no results to show. My course was part of the same faculty, and a very similar course (from English Literature to Comparative Literature which has a greater focus on foreign texts in translation rather than just those written in English), though part of two different schools, so it wasn't too difficult... Obviously my circumstances were different to your own, but it is certainly POSSIBLE to do it before you have your results, you just need to contact the relevant people to see if they will accept you.
PS. Just had a quick look online, the Social Sciences faculty falls under the same office as Humanities, so you would need to contact firstname.lastname@example.org . They were very helpful with all of my requests!
As for how clearing works, as soon as it's results day, check your UCAS track. The uni may accept you even if you've missed the grades, or they might offer you a different course. If they haven't accepted you, try phoning them.
You don't need to show a certificate- the exam board inform the university of your results so they know them before you do.