Bulb
Using heavy guage wire, cut two 12inch lenghts per bulb.
You can use proper connectors to connect to the bulb (these cost about £5 each), or you can push the wire over the pin and secure it with duct tape (its not gonna gome loose with that!)

Now that youve the wires on, strip a small piece of each and test it on the car battery to make sure theres a good connection.
Get your blank piece that you've modified, and push the bulb in as far as it will go. It should sit in place around the 3 legs, then add a few dabs of silicone just to keep it in place.