They open up, I've just cleaned and adjusted the contacts on mine as a temporary measure until I can get another one. Pop the contact out, (4 metal clips), unplug it, on the side of the boot light contact, there's 2 small slots, pop a small terminal screwdriver, (flat head) in and push the copper contact out, you'll see inside the spring mounted contact that touches the 2 small metal plates, quick squirt of contact cleaner and scrape the crap off with the screwdriver and it's good as new.