Keep in mind that LSAC does not replace grades for retaken classes, it averages them. The best net result you could get (by averaging the two grades, because both will be applied toward your LSAC GPA)is probably a B+, maybe an A- if you aced everthing. Its not going to make much difference. If you have enough credits to retake it and graduate on time, I would relax instead. A B- is no big deal. I can't imagine it being a deal breaker for any of your admissions.