Remove three bolts and the anti-sway bar link. Remove the arm, then reverse the procedure to put the new one in. It's somewhat self-explanatory when you have the new one in your hand to look at.
That's the short version. Your best bet is to get a copy of the manufacturer's service manual. It will list all the steps, with drawings and torque specs. The anti-sway bar link is not one of Chrysler's many better designs. You may want or need to replace it if you can't get the lower nut off.
The biggest thing do-it-yourselfers mess up is they bolt the new arm on while the car is supported on jack stands, then lower the car to the ground and think they're done. With any part with a rubber bushing that rotates, you must leave the bolt loose, lower the car to normal ride height, bounce it a few times, THEN crawl under the car and tighten those bolts. Tightening the bolts with the car raised lets the arms hang down. If you tighten the bolts that way, when you lower the car, those bushings will be clamped in a permanent twist and will be stressed beyond their intended limits when you drive over bumps in the road.
Don't forget that no two ball joints or control arms are the same so you'll need to have the car aligned when you're done.