It's not clear what you want to change.
Do you mean that you have a job where you get a W-2, and you want to change to being an independent contractor for the same company? If that's what you want to do you have to make the arrangements with your employer.
Or did you already change to being an independent contractor, for the same company or a different company, and you want to know how to change the version of TurboTax Online that you are using? If all of your self-employment income is shown on a Form 1099-NEC, and you have no business expenses, you can use TurboTax Deluxe Online. If you have expenses, or you have self-employment income that is not reported on a 1099-NEC, you have to use TurboTax Premium Online. When you start your tax return select the Premium edition. If you need to upgrade the edition you are using, see the following.
How do I upgrade to a different TurboTax Online product?