Как улучшить спикинг, без репетитора?

Well, from my point of view, it would be easier with a tutor, but if you're asking. So, first of all, YOU MUST PRACTICE A LOT. I don't mean practicing 1 question/part a day, NAH I mean practice a lot of questions. The concept is not knowing ANYTHING in order to speak flawlessly about something, indeed, it is about the ability to explain/justify yourself to the examiner. So, as you noticed you must spend a lot of time on enhancing your speaking abilities along with thematic vocabulary and collocations. But, if you don't want to struggle that much — read this post and take steps.