Prep well and you will raise that score in no time!!! I would prep a little bit each day. I would start by getting used to the form of each section, and then question type in each section. Do this for an hour or two after work, and a little during your lunch break if you have one/can. On your days off, I would up that to three or four hours for the first few weeks.
Once you grasp the concepts, I would move on towards timed sections. Again, one or two sections after work. About three to four months out form the testm, I would start taking a practice test once a week, and going over the test to see what you did right and wrong the next day. So spend one entire day taking the test, and the next day going over it. While going over it, it should take you nearly as long as the test itself. SO you are talking about over 3 hours for those two days.