Below is the part of the my long Fall 2013 Interior Project post that addresses cleaning the seat transmissions. I will put a link to this on our Help Page.
The 6 way power seat transmission was disassembled, cleaned and new lithium grease added. The casing comes apart via Phillips screws. Be sure to note the way the everything comes apart.
The cavity and solenoid shafts should be completely cleaned. The grease dries very hard preventing the solenoid slide plates from popping out to engage the seat cable gears. I use 0000 steel wool and WD 40 to clean shafts and cavity. Make sure the slide plates on the shafts are slid completely off the "squared" section and all dried grease is removed. I had to really bear down to get the old brown dried grease out of the cavity. Here it is nice and clean:
Ready to put back together: