Concrete pool step repair

I am trying to get some suggestions on repair of lowest step on a 25 year old concrete pool. The steps are covered with a vinyl paint and this has cracked and water can go in and raise the vinyl several inches. It compresses down but am concerned that it will progress and eventually have more of a repair. I have partially drained the pool for other reasons and can see the areas where water can seep in. I thought I might just be able to use marine epoxy to repair but see now that there are 4 large bubbles where the vinyl paint is not adherent. I asked mangers at Leslie's and said that the material should be removed, the concrete acid etched, and repainted. Would appreciate advice from forum members. Also process to do this type of repair. Thank you.