Mike
Go to Autobahn and buy a light the same size with a replaceable bulb (it will have to be a halogen).  You then have 2 options to instal -
 1) install the light using silastic to hold it in - no bolts. Install the bolts as "dummies" for the correct look.
2) cut out the bulb holder from the old light housing so it is left as a ring including the mounting tabs.  Use this as a retaining ring to slip over the new light and bolt it in. I cut mine using a dremel tool.  You need to carefully break the glass out as it is stuck in quite well.
I have used both methods and they are both great.  
Cheers Steve