The rocker panels are spot welded on both ends where they meet the door posts on the hinge side and the strike side. Additionally, they are welded on the underside. Many times, the rockers are so badly rusted that it is very difficult to determine the attachment method.

I would never discourage someone from tackling a task, however there is some welding required to properly install new rockers. Additionally, removing the old rockers may require some cutting wheel work and/or plasma cutting, depending on the condition of the old rockers. When replacing rockers, make sure to have the new pieces prior to removing the old. You want to make sure you have enough material to reattach the new units.

Best of luck.