Welcome to MINI2. Remove the side access panels in the boot. You will see a nut on a threaded rod, take this nut off. Go the lights and push against the two clips holding the light unit in. You may find it helpful to push against the rod at the same time. Don't lever the light out you may damage the paint work. When the lights come out remove the electrical connector. Plug this into your new lights, push them in place and do up the nut, replace the access panels. Done. The only difficult bit is pushing against the clips, use your new lights as guides on where to push.