I am not sure if you can do that or not Beverly. You will have to drain the whole shallow end to replace the steps and that is going to pull the liner away from the walls and, depending on how fast you can get the new steps in, poured concrete and all the other stuff, I don't think the liner will make it. Once they hold water for so long, they lose elasticity as they dry out. They get brittle and tear. I don't think it will make it. Lets see what others have to say about it.
Welcome to TFP. It would be great if you could post pics of your renovation to your steps.