I believe the dealer, and or Airstream Factory Service Center used to charge around $1700 for this service. Mine was done by a previous owner. I'd call Andy at Inland RV and see what his crew would charge, since you are in CA.
2003 GMC 2500HD 4X4 D/A Ext. Cab
Propane Powered Honda EU2000i
Lots of Hot Sauce!
Air # 283