You can buy the complete assembly with the strut, upper mount, spring, and rubber spacer all assembled. Absolutely do not try to remove the large center nut without having the spring compressed. If you are lucky, you will only lose your manhood. You may lose your life!
Many auto parts stores borrow or rent tools and they will surely have a spring compressor. The cheap pair of hooks are like toys to us professionals but they can get the job done.
Look closely at the rubber spacers under the spring. They have a metal frame inside that often rusts away. If yours are floppy and shredded, order new ones from the Chrysler dealer's parts department. Failure to install those will cause the front of the car to sit about an inch too low. They also isolate road vibration and make the car more comfortable to ride in. Better yet, just give up and sell me the car. My '93 Dynasty has been sitting in my garage for 20 years and has only 4100 miles. I love the comfort but I don't want to wear it out!