How can I get 600+ from 530??? :(

Hello, this is my second attempt to make a post here, as in the first I didn’t give a detailed report. The fact is that I need a 600+ in the GMAT, maybe before Christmas. In the first 26/09/2016 diagnostic kaplan cat I got a 460 (Q35, V17). That was my score, without studing. I am studing (...)