I'm trying to get my old battery out, but there is quite a bit of corrosion on the positive terminal. i've scraped off all the outer powder and gunk around it, but the clamp is just glued to the post. is there any special solvent or spray for this situation, or will wd-40 help? i'm asking here because since the car won't start, every time i want to get something from the store to fix it i have to walk, so i'd like to be right. oh yeah, i did loosen the nut, so we're past step one.