I recently pulled out my driver's seat to rebuild the padding and fix broken springs (will post photos). My height rails were similarly pretty frozen, though I found you must slide them to get at the bolts which attach the seat to the floor (confused me for a while). I worked them back and forth using WD-40 and other solvents, and soaking overnight in diesel fuel. I never got them where you can slide easily by hand (not much to grab hold of), but did slide with slight hammer taps. I greased with bicycle bearing grease. The seat slides up and down fairly easy in the car now. I didn't see a way to take them apart, without ruining them.