You have notes right?
Go through them and summarize them.
Then summarize the summary...
And so on until you have a nice small quantity to read before the exam.
Writing down helps the memory. Writing in colours is even better.
If you have lists to learn like the characteristics of life, create acronyms like MRS NERG... or make up a sentence using the first letter of each word if you get me.
Make flash cards....
Make word abbreviations to further shrink the quantity.
Make sure you study when you are not too tired, and take breaks in between or you will lose concentration/not take in what you are studying.
If you're really serious about good grades, take home everything you learned and spend 10 minutes or so each day re-reading and going over it, even if the exam is a year away.
Just suggestions!