The extreme in the title comes from the fact that girls in the ring are extremely hot. And wrestling because they are in a ring. Unfortunately, there is no wrestling at all. The video was produced by a Nude Model Wrestling League, very likely trying to emulate the Naked Women Wrestling League (see Nothing to Hide), but without much success.
What are they doing here? Well, one might wonder how would be an actual fight between those ladies, specially with the blonde in the yellow bikini.