Jorge,
A Southern California company made the original rub rail inserts for Ericson and they are still going strong. Take a look at their web site:
www.wefcorubber.com . My boat used "Wefco Profile:4197". The inserts, one for each side of the boat, are anchored on each end by a long bolt which is covered with end caps on the stern and a nose cap on the Bow.
Remove the caps and bolts and with some pliers slowly lift the rubber insert out of the rail.After enough of the insert is out of the rail grip it with your hands and slowly lift it out of the rail.
After cleaning the empty rail with a brush and water I started at one end of the boat and placed two or three inches of the bottom portion of the insert in the rail and then with my thumbs pressed down and inward on the top portion of the insert until it "snapped" into the rail. The new rail insert is pliable and relatively easy to "bend" into the rail. Repeat that process for another 70 feet. I can't tell you how sore my thumbs are.
After the entire new insert is in the rail, drill new holes in the ends for the "bolts" and then replace the caps.