Im trying to take it off my strut on my 03 neon sxt to change the springs.

 

There's a special tool for this #6864. A socket holds the nut but allows you to insert a hex bit through it to hold the piston shaft. You can try using an oxygen sensor with an offset square drive OR you can make your own special tool. Do this at your own risk. Find a socket to fit the large strut nut. Hold it in a vise and use a hacksaw to saw off the square drive portion of the socket. Then grind two flats on the end of the socket opposite the hex opening. Slide the socket onto the strut nut and turn it with a large adjustable wrench. Then shove a hex bit down the center of the socket to hold the strut piston while you turn the large nut. You'll sacrifice a socket, but it'll be cheaper than buying the tool.