Called around and it doesn't seem like anyone but Works can do the maintenance. I swapped the Works shock out with the original BMW shock over the weekend, which was pretty simple. The trick was setting the incoming shock to the softest setting so it was short enough to fit into place.
I sent the Works shock to CA today, $12 for two day deliver with USPS flat rate shipping. Works says it takes about 3 weeks to turn it around, $75 for new seals, another $45 if it needs a new shaft.
In the meantime, the original BMW shock seems like its in decent shape, except the rubber guide at the bottom is cracked pretty bad. Is that a deal breaker?