transferring to Kingston with not great grades but a better portfolio?

I had a quick question, I had joined a arts degree program in an American uni, but as it turned out to be a lot different from my expectations I wasn't doing too well, we barely got a single studio arts class a semester, most of our time was spent on more liberal arts related subjects, something that i didn't sign up for and was not happy with, coupled with a lack of any kind of mental health support I ended up with a rather spectacular looking mark-sheet. however, i do believe that my portfolio is in a much better state as my arts professors have always been happy with my works, and generally I've done much better in their classes, it is actually because of them that I'm planning on transferring to the UK, as a few of them sat me down on several occasions and asked me to transfer to a fine art uni course in a British or European university. The main question is now, how can I manage to get into Kingston? will I have to justify my performance in the artist statement or else in a separate document? or will something else entirely be expected of me? Kingston really does sound like a dream and I'd be so happy if I can make it in, any and all advice and guidance would be appreciated!