At some point you need to clean your parts with purple before putting it back together. Tough parts use easy off oven cleaner (with rubber gloves). Also, be careful cleaning old gasket material off. Don't use a knife or anything steel to remove the old stuff. Super stubborn stuff comes off with a nylon wire wheel.
To get the clutch nut off, the easiest way is to use an impact wrench. You need a 27mm socket anyway which is about $5 at Harbor Freight. A breaker bar will work too, but you need a clutch tool to hold it.
Here is one that I made out of a spare clutch disk.
You can buy them already made
on ebay for about $15. There is also a vice grip looking tool that you can get, but some people have had trouble with those.