My 2nd/3rd hand 2012s have been faultless until the weekend when a dust seal popped off letting loads of mud get onto the proper oil seals. I took them apart and they were spotless inside. I took the opportunity to put heavier oil in the damper to slow them down a bit as I’m a Powerful-Extreme-Trails rider.
Strip down is pretty easy, pry off compression cap and rebound dial, unscrew air cap & damper cap, bottom nuts off, pull stuff out, let oil drain all over your socks.
Do this to change oil in damper-
http://www.youtube.com/watch?feature=player_embedded&v=bDP6X4nmp9c
Put damper & air side back in, put legs on a bit then 20ml in bottom of each leg. Tighten it up and put bits back on. I’ve put 30ml of oil into the air side to get them to ramp up more, took the air valve out and used a syringe, seems easiest way.
edit, some suspension type grease under the dust seals smooths them out abit aswell.