Wings02-I finally got my MXS seat post apart (likely the same as yours)! Working on smoothing it out tomorrow. Just couldn't take another day with the "stiction" action on my ride yesterday. It sucks.... So I will be putting a craytex bit on the edges (The bearing surface is 90*, not beveled). I think this will improve the sliding action between the nylon/plastic, and the inside of the seat tube. There was also some chrome plating flaking off in the seat tube, as no doubt Wings02 has seen. This however, isn't the problem. I believe the inexact dimensions between the nylon and the hollow seat tube, coupled by the 90* edge tilting into/away from the seat tube. Thoughts? I'll have more T&E on this tomorrow. I tried to protect the tube with painters tape, but since its at the bottom, I'm not bothered it got boogered up. You NEED a vise (under the jaws of most regular vises contain a "V" shaped pipe holder.
1. Use a set of snap ring pliers to remove snap ring under seat post.
2. Use a 6mm allen wrench to fully remove silver screw under snap ring.
3. Remove the spring (its in a plastic bag, assumingely for lubricity.
You need some sort of pipe holder for a vise if you don't have this feature. Once in a vise, a large adjustable wrench on the flats of the second pic (lefty loosey) and if the seat tube isn't spinning, it will finally break free.
4. Once you get it fully unscrewed, it takes several HARD pops to pull the nylon fitting out that is attached to the seat
Note* the roll pin won't help you if you remove it. The seat base is pressed into that piece. I couldn't get it to budge.