Exercise is paramount if you have a slow metabolism. It amps up all your body's systems to a more rapid state of homeostasis.

If you dont like aerobic exercise, just try to walk more often and longer.

As far as the BMR - in my case I am able to lose if I stay right at or just above my BMR. My BMR is around 2300, so if I stay at 2000-2500, I consistently lose, but I am also exercising reguarly.