'93 Grand Voyager headlight problem

I need to replace the part that holds the halogen bulb, but I haven't figured out how to get the old one off (I think it's the back of the headlight assembly...the bulb sticks through it and the retaining ring holds the bulb in.

Thanks

Check this post for help. Its about # 100 in the list. 95 Caravan 3.0L --> How to remove headlamp housing? I'll check in later to see how ya did. Good luck!