This is how I converted my front parking lamps into dual filament park/turn lamps. Granted your's will be slightly different being a B3 vrs. my B2, but the principal remains the same.
I found these sockets at a local parts store. (I believe it was a Checker, which is now O'Reilly)
I then figured out how to remove the sockets from my lamp housings. All it took was to heat them up and tap them out. They were just soldered in.
Then I just soldered the new one in place and painted it all up nice.
My next problem was that my lenses are clear glass and I couldn't find amber bulbs in 6 volt. So I got some amber LED replacement bulbs from superbrightleds.com. And since I made all of my harnesses, I just added the wires for the front turn signals as I assembled everything. Maybe RI wire can add your front signal wires too. The only problems comes in the fact that the parking lamp wire connects to the junction strips along side the radiator. There are only 3 terminals on those strips. 2 for the headlamps and 1 for the parking lamp. When I wired up mine I used the 3 terminals for the headlamps (Hi beam, lo beam, and ground) and added a couple of small connectors for the parking/turn signal lamps.
Merle