Do the LSAT course, and really devote yourself to it. If you truly practice what they teach, you should be able to improve your LSAT score.
Read. Read a lot. Read something like the NY Times, daily. Something that requires a certain degree of analysis. That will help.
Take a sample LSAT test now, as you would in real life. Timed, in silence, etc. See how you score now, without prep, so you know what you're up against.