I actually just refurbished my front active aero assembly for the very same reason. Good luck!
My issue was the cap on the motor rusted off, and let water inside to gum things up. So I removed it, gave everything a rust removal bath, re-greased the cogs, cleaned electrical connectors, put everything back together, built a new cap and painted everything with rustoleum. The rods that move the plastic spoiler up and down were also rusty, so I took the assembly apart, sanded off the rust, used some boat grease and put that back together. It was a pain in the butt, but well worth it because everything works now :). I also rebuilt the rear aero motor and assembly. Be very careful if you take the motors apart. Make sure everything is in the disengaged (up in front and down in back) before taking stuff apart. Also, take pictures of EVERYTHING while you take things apart, little pieces tend to fly everywhere. Joe has a nice video on YouTube with some tips too.
Let me know if you run into any issues, maybe I can give you a hand, remotely :).