Once you take the lens off, you will see the
light base is held on by two rivets, drill them out and you can mount the new fixture. Most dealers will have the same style as original. Just be careful when you drill the old one out, as it's pretty easy to drill right through the ensolite on the inside. I would solder the connection where the wires join and heat shrink over top, but a good quality crimper and crimps will work. If you do crimp, make sure you tape or heat shrink over the splice.
Joe