I assme that this is for a state return, You will need to amend the state return, and mail it to the state taxing authority per the instructions. Note that this may change your federal return - if it does, you will have to mail the 1040X to the IRS as well; if it doesn't, don't worry about it.
When you get into the state in TurboTax, remove what you did to indicate the rent that you paid. I assume that this will remove some renter's credit (depends on where you are).
When you are finished with the amendment, double check it to make sure that your renter's credit (or whatever benefit you got) is gone. Then talk to your parents and offer to give them a copy of your state return showing that you are no longer taking the renter's credit in case they want to attach it to their response to the state taxing authority.
Please see this TurboTax FAQ for how to amend your return with TurboTax - https://ttlc.intuit.com/replies/3288565
