Before we begin, let's get one thing out of the way: if you haven't already studied for the LSAT for at least 1-2 months, there is little you can do in the last week before the test. Yes, life can get in the way and sometimes even the best-laid plans go astray. Unfortunately, you cannot cram for the LSAT: it's a test of how you think, not how much you know.
Unlike most knowledge-based tests, the LSAT measures whether you possess the skill set necessary to excel in law school: close reading, critical reasoning, rule application, information synthesis, and the like. These are skills we develop over time, not in one week. So, if you've been putting off this LSAT project until the last week before the test, you may be better off taking the test in January instead. Plan your studies accordingly.