What to use to replace this ptrap

[gray10b]

Can you tell me what type of p trap this is and do you have any suggestions for the simplest way to replace it (with PVC?). I don't understand how the coupling on the wall side works. We have a clog and I can't get at the cleanout (and even if I could it looks pretty corroded) so I think I have to remove the pedestal to get at it. Even there I'm not sure how to loosen the ptrap coupling on the sink side before trying to remove the pedestal because it is so tight back there. If I have to remove the pedestal I'd rather replace what's there with something where I won't have to remove the pedestal next time there's a clog.
Thanks for any suggestions.

 

[Geofd]

more than likely thats a galvanized nipple under that chrome sleeve
you will have to remove the pedestal
you have 2 choices
1.cut it close to the wall, leaving enough room for a stainless steel 4 band coupling and a trap with a union connection
2. cut the pipe slide the chrome sleeve off, you should see the galvi pipe, with a pipe wrench grab the pipe close to the wall and back the nipple out not the easiest but at least you will get rid of the old pipe
3. if you didn't want to do anything but clear the drain there are small rubber plugs, used in urinals, you could drill out the clean out and use one of those plugs just make sure the head of the snake will fit thru the hole,there are plugs out there 3/4+7/8 in diameter....kohler maked the urinal plug

 

[gray10b]

Thank you for your advice, that is very helpful.