Best buy black tie protection- laptop battery and charger replacement?

So I purchased my laptop along with the black tie protection, which is a 2 yr plan , around fall of '09, and I'm wondering now, what would I have to do in order to get the new battery/charger now that my laptop is telling me it needs a replacement? or how do I even know if my plan is still valid? I never used it before so I have no idea.