Illnesses: Infant, Medela

Used Medela Pump

Hi Ladies, I bought a used Medela pump from a friend. I bought all replacement parts for it, the tubes being the main concern. Even though I bought new ones, I think they should be sterilized. How should I do it? Im afraid boiling them will melt it and Im afraid to put it in the dishwasher with detergent and get soap chemicals stuck in them. I realllllly dont want to go buy a sterilizer. And do you sterilize them often? I dont know! Any thoughts?