What should I do to make into Toxicology Graduate program for MS in my current situation?

[Toxico]

I just graduated UC Berkeley as BA of Molecular and Cell Bio with 3.1 GPA. As an international student, I am just afraid to get in MS toxicology program with low GPA. I have 3.65 GPA from Toxicology and Nutri Sci courses but tremendously low on my major. I am not expected to be in so called top-tier grad school for my MS. I have 6 years total research experience. 2 years (diabetes), 2 years (cancer stem cell), 1 year (optical) at Korea University working for a same professor (only during summer since high school). full 1 year at one of genetics lab at UC Berkeley. I am about to take GRE and GRE subject tests (Bio and Chem) from August to October. Can any of you actually guide me what to do till this December for application? Also, which school do I have to apply for?