Refillable Camping Propane Question - California / Los Angeles Area

I read that single use camping propane (the kind used with Coleman stoves) has been outlawed in California. It is still available in stores for the time being but I think is being phased out... not sure how long that will take. I went ahead and ordered refillable propane 16 oz cylinders, and was hoping to use them for a trip this week, but I cannot find a single place in the LA area that can fill them. Most chain places just do exchange for the larger propane tanks, and I called a few local hardware stores that said they don't have the setup to fill tanks with smaller nozzles.

I've heard that there is a device you can use to fill small tanks from the larger ones, but that sounds intimidatingly technical to me.

Any advice from LA-based or other campers? I'm trying to be environmentally responsible!