Just a case of unscrewing the cable from the post, take the post out, then unscrew the collar. Be careful when taking the collar off as the rubber boot twists too, but you can just hold onto it and undo the collar a small bit at a time. Once the collar is undone just pull the post apart. Its very basic inside, not much to it.
Mine stopped working after its first ride out, which was a shitty wet day on gritty trails, but still not great. Stripped it and bunged a load of grease in it and its working well again. Yet to hit the trails with it again, so we'll see. Pretty sure most of the crap that stopped it from working got in from the top off the boot (2013 version), so I've put a cable tie around the top to see if that helps.