Some years ago the lift truck drivers ruined the rub rail on both sides of my Grady by putting it in/out of the dry slip. The guy who repaired it was really PO'd at the truck drivers because it was a lot of work.
I installed a new rub rail on an 18 ft. boat a few months ago. Do it in the sun if you can to keep the new rub rail flexible. A heavey rubber mallet and a large screw driver (dull chisel) with a very wide blade is helpful. A second person is helpful also. Take a few aspirins before you go to bed. Your shoulders will hurt.