imo switch to using an impact driver, mine did the same, $50 corded impact driver from harbor freight is perfect for automotive jobs if you don't go HAM with it.
If you must have them fixed your best bet is to just send them down to Bilstein in Poway, the only other shop I know that might fix it is PSI in Sonoma but they may be distracted at the moment and likely charge more than Bilstein US to do the exact same job. Which will likely be to just replace the damper body, if not the whole damper, and charge you accordingly.
I'm trying to find a link to Bilstein US service but they've "upgraded" their website and it's damn near impossible now...
A machine shop may be able to do something for you, but I don't know what they would attempt or how well it would work. jmho switch to using an impact.