Samsung Fascinate Dock
The first thing you have to do is disassemble the dock. I managed to mangle this dock pretty badly trying to do that, but the trick with Samsung docks is to pry the back panel of first, then the screws and finally pop off the front. You'll end up with three pieces.
We are concerned primarily with the front piece. Remove all the wires and get the front piece by itself. Now, break out a small file, a knife, some wire cutter and whatever other sharp implements you may want. I then start cutting away all the excess plastic above the original USB plug, as we need to move the plug up and forward in order to accommodate the taller and thicker GN. I actually ended up cutting away the plastic around the plug entirely as I found that the plug was too thick to be able to leave everything in place.
As you can see, I cut a new notch for the USB plug as well as took off all the material around it. Now do a test fit. if you find everything fitting nicely then tack the plug into place with some superglue. Do this CAREFULLY with the phone still in place in order to make sure that everything fits once dried. Once this dries, remove the phone, and reinforce the area with more superglue or epoxy. The end result should look something like this:
As you can see I filed down the plug a bit. This was not necessary, but I did it because I was trying to avoid cutting the front of the dock. Before reassembling everything plug the dock and the phone in and verify that it still in fact works. Now reassemble. Congrats! You have a Galaxy Nexus multimedia dock! The only issue I'm currently running into is that the line out via USB is not working. I'm not sure if this is a dock issue (resistor value wrong for the ID pin) or if its a phone/ROM issue. FYI the Fascinate dock ID resistor value is 365k.
The finished dock:
Have fun and happy modding!